answers (lesson 10-1) - merrimack high school...1 3 x 1 8 the degree of a quadratic function is 2,...

21
© Glencoe/McGraw-Hill A2 Glencoe Algebra 1 Study Guide and Intervention Graphing Quadratic Functions NAME ______________________________________________ DATE ____________ PERIOD _____ 10-1 10-1 © Glencoe/McGraw-Hill 579 Glencoe Algebra 1 Lesson 10-1 Graph Quadratic Functions Quadratic a function described by an equation of the form f (x ) = ax 2 + bx + c, Example: Function where a 0 y = 2x 2 + 3x + 8 The degree of a quadratic function is 2, and the exponents are positive. Graphs of quadratic functions have a general shape called a parabola. A parabola opens upward and has a minimum point when the value of a is positive, and a parabola opens downward and has a maximum point when the value of a is negative. Use a table of values to graph y = x 2 - 4x + 1. Graph the ordered pairs in the table and connect them with a smooth curve. x y O x y -1 6 0 1 1 -2 2 -3 3 -2 4 1 Use a table of values to graph y =-x 2 - 6x - 7. Graph the ordered pairs in the table and connect them with a smooth curve. x y O x y -6 -7 -5 -2 -4 1 -3 2 -2 1 -1 -2 0 -7 Example 1 Example 1 Example 2 Example 2 Exercises Exercises Use a table of values to graph each function. 1. y = x 2 + 2 2. y =-x 2 - 4 3. y = x 2 - 3x + 2 x y O x y O x y O © Glencoe/McGraw-Hill 580 Glencoe Algebra 1 Symmetry and Vertices Parabolas have a geometric property called symmetry. That is, if the figure is folded in half, each half will match the other half exactly. The vertical line containing the fold line is called the axis of symmetry. Axis of For the parabola y = ax 2 + bx + c, where a 0, Example: The axis of symmetry of Symmetry the line x =- is the axis of symmetry. y = x 2 + 2x + 5 is the line x =-1. The axis of symmetry contains the minimum or maximum point of the parabola, the vertex. Consider the graph of y = 2x 2 + 4x + 1. b 2a Study Guide and Intervention (continued) Graphing Quadratic Functions NAME ______________________________________________ DATE ____________ PERIOD _____ 10-1 10-1 Example Example a. Write the equation of the axis of symmetry. In y = 2x 2 + 4x + 1, a = 2 and b = 4. Substitute these values into the equation of the axis of symmetry. x =- x =- =-1 The axis of symmetry is x =-1. 4 2(2) b 2a b. Find the coordinates of the vertex. Since the equation of the axis of symmetry is x =-1 and the vertex lies on the axis, the x-coordinate of the vertex is -1. y = 2x 2 + 4x + 1 Original equation y = 2(-1) 2 + 4(-1) + 1 Substitute. y = 2(1) - 4 + 1 Simplify. y =-1 The vertex is at (-1, -1). c. Identify the vertex as a maximum or a minimum. Since the coefficient of the x 2 -term is positive, the parabola opens upward, and the vertex is a minimum point. d. Graph the function. x y O ( –1, –1 ) x = –1 Exercises Exercises Write the equation of the axis of symmetry, and find the coordinates of the vertex of the graph of each function. Identify the vertex as a maximum or a minimum. Then graph the function. 1. y = x 2 + 3 2. y =-x 2 - 4x - 4 3. y = x 2 + 2x + 3 x = 0; (0, 3); min x =-2; (-2, 0); max x =-1; (-1, 2); min x y O x y O x y O Answers (Lesson 10-1)

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Page 1: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A2 Glencoe Algebra 1

Stu

dy G

uid

e a

nd I

nte

rven

tion

Gra

ph

ing

Qu

ad

rati

c F

un

cti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

©G

lencoe/M

cG

raw

-Hill

579

Gle

ncoe A

lgebra

1

Lesson 10-1

Gra

ph

Qu

ad

rati

c Fu

nct

ion

s

Qu

ad

rati

ca f

unction d

escribed b

y a

n e

quation o

f th

e f

orm

f(x

) 5

ax

21

bx

1c,

Exam

ple

:

Fu

ncti

on

where

0y

52x

21

3x

18

Th

e d

egre

e o

f a q

uad

rati

c fu

nct

ion

is

2,an

d t

he e

xp

on

en

ts a

re p

osi

tive.G

rap

hs

of

qu

ad

rati

cfu

nct

ion

s h

ave a

gen

era

l sh

ap

e c

all

ed

a p

ara

bo

la.A

para

bola

op

en

s u

pw

ard

an

d h

as

am

inim

um

po

int

wh

en

th

e v

alu

e o

f a

is p

osi

tive,an

d a

para

bola

op

en

s d

ow

nw

ard

an

d h

as

am

ax

imu

m p

oin

tw

hen

th

e v

alu

e o

f a

is n

egati

ve.

Use a

ta

ble

of

va

lues t

o

gra

ph

y5

x2

24x

11.

Gra

ph

th

e o

rdere

d p

air

s in

th

e t

able

an

dco

nn

ect

th

em

wit

h a

sm

ooth

cu

rve.x

y

O

xy

21

6

01

12

2

22

3

32

2

41

Use a

ta

ble

of

va

lues t

o

gra

ph

y5

2x

22

6x

27.

Gra

ph

th

e o

rdere

d p

air

s in

th

e t

able

an

dco

nn

ect

th

em

wit

h a

sm

ooth

cu

rve.

x

y

O

xy

26

27

25

22

24

1

23

2

22

1

21

22

02

7

Example

1Example

1Example

2Example

2

Exercises

Exercises

Use a

ta

ble

of

va

lues t

o g

ra

ph

ea

ch

fu

ncti

on

.

1.

y5

x2

12

2.

y5

2x

22

43.

y5

x2

23

x1

2

x

y

O

x

y

O

x

y

O

©G

lencoe/M

cG

raw

-Hill

580

Gle

ncoe A

lgebra

1

Sym

metr

y a

nd

Vert

ices

Para

bola

s h

ave a

geom

etr

ic p

rop

ert

y c

all

ed

sy

mm

etr

y.T

hat

is,if

th

e f

igu

re i

s fo

lded

in

half

,each

half

wil

l m

atc

h t

he o

ther

half

exact

ly.T

he v

ert

ical

lin

eco

nta

inin

g t

he f

old

lin

e i

s ca

lled

th

e a

xis

of

sy

mm

etr

y.

Axis

of

For

the p

ara

bola

y5

ax

21

bx

1c,

where

0,

Exam

ple

:T

he a

xis

of

sym

metr

y o

f

Sym

metr

yth

e lin

e x

52

is t

he a

xis

of

sym

metr

y.y

5x

21

2x

15 is t

he lin

e x

52

1.

Th

e a

xis

of

sym

metr

y c

on

tain

s th

e m

inim

um

or

maxim

um

poin

t of

the p

ara

bola

,th

e v

erte

x.

Co

nsid

er t

he g

ra

ph

of

y5

2x

21

4x

11.

b} 2

a

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

Gra

ph

ing

Qu

ad

rati

c F

un

cti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

Example

Example

a.

Writ

e t

he e

qu

ati

on

of

the a

xis

of

sy

mm

etr

y.

In y

52

x2

14

x1

1,a

52 a

nd

b5

4.

Su

bst

itu

te t

hese

valu

es

into

th

e e

qu

ati

on

of

the a

xis

of

sym

metr

y.

x5

2

x5

25

21

Th

e a

xis

of

sym

metr

y i

s x

52

1.

4} 2

(2)

b} 2

a

b.

Fin

d t

he c

oo

rd

ina

tes o

f th

e v

erte

x.

Sin

ce t

he e

qu

ati

on

of

the a

xis

of

sym

metr

y i

s x

52

1 a

nd

th

e v

ert

ex l

ies

on

th

e a

xis

,th

e x

-coord

inate

of

the v

ert

ex

is 2

1.

y5

2x

21

4x

11

Origin

al equation

y5

2(2

1)2

14(2

1)

11

Substitu

te.

y5

2(1

) 2

4 1

1S

implif

y.

y5

21

Th

e v

ert

ex i

s at

(21,

21).

c.

Iden

tify

th

e v

erte

x a

s a

ma

xim

um

or

a m

inim

um

.

Sin

ce t

he c

oeff

icie

nt

of

the x

2-t

erm

is

posi

tive,th

e p

ara

bola

op

en

s u

pw

ard

,an

dth

e v

ert

ex i

s a m

inim

um

poin

t.

d.

Gra

ph

th

e f

un

cti

on

.

x

y O

( –1, –1)

x 5

–1

Exercises

Exercises

Writ

e t

he e

qu

ati

on

of

the a

xis

of

sy

mm

etr

y,

an

d f

ind

th

e c

oo

rd

ina

tes o

f th

e v

erte

x

of

the g

ra

ph

of

ea

ch

fu

ncti

on

.Id

en

tify

th

e v

erte

x a

s a

ma

xim

um

or a

min

imu

m.

Th

en

gra

ph

th

e f

un

cti

on

.

1.

y5

x2

13

2.

y5

2x

22

4x

24

3.

y5

x2

12

x1

3

x5

0;

(0,3);

min

x5

22;

(22,0);

max

x5

21;

(21,2);

min

x

y

O

x

y

O

x

y

O

Answers (Lesson 10-1)

Page 2: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A3 Glencoe Algebra 1

An

swers

Skil

ls P

racti

ce

Gra

ph

ing

Qu

ad

rati

c F

un

cti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

©G

lencoe/M

cG

raw

-Hill

581

Gle

ncoe A

lgebra

1

Lesson 10-1

Use a

ta

ble

of

va

lues t

o g

ra

ph

ea

ch

fu

ncti

on

.

1.

y5

x2

24

2.

y5

2x

21

3

3.

y5

x2

22

x2

64.

y5

2x

22

4x

11

Writ

e t

he e

qu

ati

on

of

the a

xis

of

sy

mm

etr

y,

an

d f

ind

th

e c

oo

rd

ina

tes o

f th

e v

erte

x

of

the g

ra

ph

of

ea

ch

fu

ncti

on

.Id

en

tify

th

e v

erte

x a

s a

ma

xim

um

or m

inim

um

.

Th

en

gra

ph

th

e f

un

cti

on

.

5.

y5

2x

26.

y5

x2

22

x2

57.

y5

2x

21

4x

21

x5

0;

(0,0);

min

x5

1;

(1,

26);

min

x5

2;

(2,3);

max

8.

y5

2x

22

2x

12

9.

y5

2x

21

4x

22

10.

y5

22

x2

24x

16

x5

21;

(21,3);

max

x5

21;

(21,

24);

min

x5

21;

(21,8);

max

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

x

y

O

©G

lencoe/M

cG

raw

-Hill

582

Gle

ncoe A

lgebra

1

Use a

ta

ble

of

va

lues t

o g

ra

ph

ea

ch

fu

ncti

on

.

1.

y5

2x

21

22.

y5

x2

26

x1

33.

y5

22x

22

8x

25

Writ

e t

he e

qu

ati

on

of

the a

xis

of

sy

mm

etr

y,

an

d f

ind

th

e c

oo

rd

ina

tes o

f th

e v

erte

x

of

the g

ra

ph

of

ea

ch

fu

ncti

on

.Id

en

tify

th

e v

erte

x a

s a

ma

xim

um

or m

inim

um

.

Th

en

gra

ph

th

e f

un

cti

on

.

4.

y5

2x

21

35.

y5

22x

21

8x

23

6.

y5

2x

21

8x

11

x5

0;

(0,3);

max

x5

2;

(2,5);

max

x5

22;

(22,

27);

min

PH

YS

ICS

Fo

r E

xercis

es 7

–9,

use t

he f

oll

ow

ing

in

form

ati

on

.

Mir

an

da t

hro

ws

a s

et

of

keys

up

to h

er

bro

ther,

wh

o i

s st

an

din

g o

n a

th

ird

-sto

ry b

alc

on

yw

ith

his

han

ds

38 f

eet

above t

he g

rou

nd

.If

Mir

an

da t

hro

ws

the k

eys

wit

h a

n i

nit

ial

velo

city

of

40 f

eet

per

seco

nd

,th

e e

qu

ati

on

h5

216t2

140t

15 g

ives

the h

eig

ht

hof

the k

eys

aft

er

tse

con

ds.

7.

How

lon

g d

oes

it t

ak

e t

he k

eys

to r

each

th

eir

hig

hest

poin

t?1.2

5 s

8.

How

hig

h d

o t

he k

eys

reach

?30 f

t

9.

Wil

l h

er

bro

ther

be a

ble

to c

atc

h t

he k

eys?

Exp

lain

.N

o,th

e k

eys w

ill

be 8

ft

sh

ort

of

their

targ

et.

BA

SE

BA

LL

Fo

r E

xercis

es 1

0–12,

use t

he f

oll

ow

ing

in

form

ati

on

.

A p

layer

hit

s a b

ase

ball

at

a 4

an

gle

wit

h t

he g

rou

nd

wit

h a

n i

nit

ial

velo

city

of

80 f

eet

per

seco

nd

fro

m a

heig

ht

of

thre

e f

eet

above t

he g

rou

nd

.T

he e

qu

ati

on

h5

20.0

05x

21

x1

3 g

ives

the p

ath

of

the b

all

,w

here

his

th

e h

eig

ht

an

d x

is t

he h

ori

zon

tal

dis

tan

ce t

he b

all

tra

vels

.

10.W

hat

is t

he e

qu

ati

on

of

the a

xis

of

sym

metr

y?

x5

10

0

11.W

hat

is t

he m

axim

um

heig

ht

reach

ed

by t

he b

ase

ball

?53 f

t

12.A

n o

utf

ield

er

catc

hes

the b

all

th

ree f

eet

above t

he g

rou

nd

.H

ow

far

has

the b

all

tra

vele

dh

ori

zon

tall

y w

hen

th

e o

utf

ield

er

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hes

it?

200 f

t

x

y

O

x

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x

y

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x

y O

x

y

Ox

y

OPra

cti

ce (

Avera

ge)

Gra

ph

ing

Qu

ad

rati

c F

un

cti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

Answers (Lesson 10-1)

Page 3: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A4 Glencoe Algebra 1

Readin

g t

o L

earn

Math

em

ati

cs

Gra

ph

ing

Qu

ad

rati

c F

un

cti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

©G

lencoe/M

cG

raw

-Hill

583

Gle

ncoe A

lgebra

1

Lesson 10-1

Pre

-Act

ivit

yH

ow

ca

n y

ou

co

ord

ina

te a

fir

ew

ork

s d

isp

lay

wit

h r

eco

rd

ed

mu

sic?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-1

at

the

top

of

page

524 i

n y

our

textb

ook

.

Acc

ord

ing t

o th

e gra

ph

,at

wh

at

hei

gh

t d

oes

the

rock

et e

xp

lod

e an

d i

n h

owm

an

y s

econ

ds

aft

er b

ein

g l

au

nch

ed?

It e

xp

lod

es a

t a h

eig

ht

of

80 m

ete

rs 4

seco

nd

s a

fter

bein

g l

au

nch

ed

.

Read

ing

th

e L

ess

on

1.

Th

e st

an

dard

for

m f

or a

fu

nct

ion

is

y5

ax

21

bx

1c.

For

th

e

fun

ctio

n y

52

x2

25

x1

3,th

e valu

e of

ais

,th

e valu

e of

bis

,an

d

the

valu

e of

cis

.

2.

Th

e gra

ph

s of

tw

o qu

ad

rati

c fu

nct

ion

s are

sh

own

bel

ow.C

omp

lete

each

sta

tem

ent

abou

tth

e gra

ph

s.

A.

B.

a.

Each

gra

ph

is

a c

urv

e ca

lled

a

.

b.

Th

e h

igh

est

poi

nt

of g

rap

h A

is

loca

ted

at

.T

his

poi

nt

is t

he

(maxim

um

/min

imu

m)

poi

nt

of t

he

gra

ph

.

c.

Th

e lo

wes

t p

oin

t of

gra

ph

B i

s lo

cate

d a

t .T

his

poi

nt

is t

he

(maxim

um

/min

imu

m)

poi

nt

of t

he

gra

ph

.

3.

Th

e m

axim

um

or

min

imu

m p

oin

t of

a p

ara

bol

a i

s ca

lled

th

e of

th

e p

ara

bol

a.

4.

If y

ou f

old

a p

ara

bol

a a

lon

g a

lin

e to

get

tw

o h

alv

es t

hat

matc

h e

xact

ly,th

e li

ne

wh

ere

you

fol

d t

he

para

bol

a i

s th

e of

th

e p

ara

bol

a.T

his

lin

e goe

s

thro

ugh

th

e of

th

e p

ara

bol

a.

5.

For

a q

uad

rati

c fu

nct

ion

y5

ax

21

bx

1c,

the

para

bol

a o

pen

s u

pw

ard

if

a0.

It o

pen

s d

own

ward

if

a0.

Help

ing

Yo

u R

em

em

ber

6.

Loo

k u

p t

he

wor

d v

erte

xin

a d

icti

onary

.Y

ou w

ill

fin

d t

hat

it c

omes

fro

m t

he

Lati

n w

ord

ver

tere

,w

hic

h m

ean

s to

tu

rn.H

ow c

an

you

use

th

e id

ea o

f “t

o tu

rn”

to r

emem

ber

wh

at

the

ver

tex o

f a p

ara

bol

a i

s?S

am

ple

an

sw

er:

Th

e v

ert

ex o

f a p

ara

bo

la i

s t

he

po

int

at

wh

ich

th

e p

ara

bo

la t

urn

s u

pw

ard

or

do

wn

ward

.

,

.

vert

ex

axis

of

sym

metr

y

vert

ex

min

imu

m

(21,

22)

ma

xim

um

(21,4)

para

bo

la

x

y

O

x

y

O

3

25

2

qu

ad

rati

c

©G

lencoe/M

cG

raw

-Hill

584

Gle

ncoe A

lgebra

1

Tra

nsla

tin

g Q

uad

rati

c G

rap

hs

Wh

en a

fig

ure

is

mov

ed t

o a n

ew p

osit

ion

wit

hou

t u

nd

ergoi

ng a

ny r

otati

on,th

en t

he

figu

re i

s sa

id t

o h

ave

bee

n t

ran

sla

ted

to t

hat

pos

itio

n.

Th

e gra

ph

of

a q

uad

rati

c eq

uati

on i

n t

he

form

y

5(x

2b)2

1c

is a

tra

nsl

ati

on o

f th

e gra

ph

of

y5

x2.

Sta

rt w

ith

y5

x2.

Sli

de

to t

he

righ

t 4 u

nit

s.

y5

(x2

4)2

Th

en s

lid

e u

p 3

un

its.

y5

(x2

4)2

13

Th

ese

eq

ua

tio

ns

ha

ve t

he f

orm

y5

x2

1c.

Gra

ph

ea

ch

eq

ua

tio

n.

1.

y5

x2

11

2.

y5

x2

12

3.

y5

x2

22

Th

ese

eq

ua

tio

ns

ha

ve t

he f

orm

y5

(x2

b)2

.G

ra

ph

ea

ch

eq

ua

tio

n.

4.

y5

(x2

1)2

5.

y5

(x2

3)2

6.

y5

(x1

2)2

x

y Ox

y Ox

y O

x

y Ox

y Ox

y O

x

y O

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-1

10-1

Answers (Lesson 10-1)

Page 4: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A5 Glencoe Algebra 1

An

swers

Stu

dy G

uid

e a

nd I

nte

rven

tion

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y G

rap

hin

g

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

©G

lencoe/M

cG

raw

-Hill

585

Gle

ncoe A

lgebra

1

Lesson 10-2

So

lve b

y G

rap

hin

g

Qu

ad

rati

c E

qu

ati

on

an e

quation o

f th

e f

orm

ax

21

bx

1c

50,

where

0

Th

e so

luti

ons

of a

qu

ad

rati

c eq

uati

on a

re c

all

ed t

he

roo

tsof

th

e eq

uati

on.T

he

root

s of

a q

uad

rati

c eq

uati

on c

an

be

fou

nd

by g

rap

hin

g t

he

rela

ted

qu

ad

rati

c fu

nct

ion

f(

x)

5a

x2

1bx

1c

an

d f

ind

ing t

he

x-i

nte

rcep

ts o

r zero

sof

th

e fu

nct

ion

.

So

lve x

21

4x

13 5

0 b

yg

ra

ph

ing

.

Gra

ph

th

e re

late

d f

un

ctio

n f

(x)

5x

21

4x

13.

Th

e eq

uati

on o

f th

e axis

of

sym

met

ry i

s

x5

2or

22.T

he

ver

tex i

s at

( 2

2,

21).

Gra

ph

th

e ver

tex a

nd

sev

eral

oth

er p

oin

ts o

nei

ther

sid

e of

th

e axis

of

sym

met

ry.

To

solv

e x

21

4x

13 5

0,you

nee

d t

o k

now

wh

ere

the

valu

e of

f(x

) 5

0.T

his

occ

urs

at

the

x-i

nte

rcep

ts,

23 a

nd

21.

Th

e so

luti

ons

are

23 a

nd

21.

xO

f(x)

4} 2

(1)

So

lve x

22

6x

19 5

0 b

yg

ra

ph

ing

.

Gra

ph

th

e re

late

d f

un

ctio

n f

(x)

5x

22

6x

19.

Th

e eq

uati

on o

f th

e axis

of

sym

met

ry i

s

x5

or 3

.T

he

ver

tex i

s at

( 3,0).

Gra

ph

the

ver

tex a

nd

sev

eral

oth

er p

oin

ts o

n e

ith

ersi

de

of t

he

axis

of

sym

met

ry.

To

solv

e x

22

6x

19 5

0,you

nee

d t

o k

now

wh

ere

the

valu

e of

f(x

) 5

0.T

he

ver

tex o

f th

ep

ara

bol

a i

s th

e x-i

nte

rcep

t.T

hu

s,th

e on

lyso

luti

on i

s 3.

x

f(x) O

6} 2

(1)

Example

1Example

1Example

2Example

2

Exercises

Exercises

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.

1.

x2

17x

112 5

02.

x2

2x

212 5

03.

x2

24

x1

5 5

0

23;

24

4,

23

no

real

roo

ts

x

f (x)

O

x

f (x)

O4

4

24

28

212

82

42

8

x

f (x)

O

©G

lencoe/M

cG

raw

-Hill

586

Gle

ncoe A

lgebra

1

Est

imate

So

luti

on

sT

he

root

s of

a q

uad

rati

c eq

uati

on m

ay n

ot b

e in

teger

s.If

exact

root

s ca

nn

ot b

e fo

un

d,th

ey c

an

be

esti

mate

d b

y f

ind

ing t

he

con

secu

tive

inte

ger

s bet

wee

nw

hic

h t

he

root

s li

e. So

lve x

21

6x

16 5

0 b

y g

ra

ph

ing

.If

in

teg

ra

l ro

ots

ca

nn

ot

be f

ou

nd

,est

ima

te t

he r

oo

ts b

y s

tati

ng

th

e c

on

secu

tiv

e i

nte

gers

betw

een

wh

ich

th

e r

oo

ts l

ie.

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y G

rap

hin

g

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

Example

Example

Gra

ph

th

e re

late

d f

un

ctio

n f

(x)

5x

21

6x

16.

Not

ice

that

the

valu

e of

th

e fu

nct

ion

ch

an

ges

fr

om n

egati

ve

to p

osit

ive

bet

wee

n t

he

x-v

alu

es

of 2

5 a

nd

24 a

nd

bet

wee

n 2

2 a

nd

21.

xf(

x)

25

1

24

22

23

23

22

22

21

1

x

f(x)

O

Exercises

Exercises

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.If

in

teg

ra

l ro

ots

ca

nn

ot

be f

ou

nd

,est

ima

te t

he

ro

ots

by

sta

tin

g t

he c

on

secu

tiv

e i

nte

gers

betw

een

wh

ich

th

e r

oo

ts l

ie.

1.

x2

17x

19 5

02.

x2

2x

24 5

03.

x2

24x

16 5

0

26 ,

x,

25,

22 ,

x,

21,

no

real

roo

ts2

2 ,

x,

21

2 ,

x,

3

4.

x2

24x

21 5

05.

4x

22

12x

13 5

06.

x2

22x

24 5

0

21 ,

x,

0,

0 ,

x,

1,

22 ,

x,

21,

4 ,

x,

52 ,

x,

33 ,

x,

4

x

f (x)

O

x

f (x)

O

x

f (x)

O

x

f (x)

O

x

f (x)

O

x

f (x)

O

Th

e x-i

nte

rcep

ts o

f th

e gra

ph

are

bet

wee

n 2

5 a

nd

24 a

nd

bet

wee

n 2

2 a

nd

21.

So

one

root

is

bet

wee

n 2

5 a

nd

24,an

d t

he

oth

er r

oot

is b

etw

een

22 a

nd

21.

Answers (Lesson 10-2)

Page 5: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A6 Glencoe Algebra 1

Skil

ls P

racti

ce

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y G

rap

hin

g

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

©G

lencoe/M

cG

raw

-Hill

587

Gle

ncoe A

lgebra

1

Lesson 10-2

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.

1.

x2

24x

15 5

0[

2.

c21

6c

18 5

02

4,

22

3.

a2

22a

52

11

4.

n2

27

n5

210

2,5

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.If

in

teg

ra

l ro

ots

ca

nn

ot

be f

ou

nd

,est

ima

te t

he

ro

ots

by

sta

tin

g t

he c

on

secu

tiv

e i

nte

gers

betw

een

wh

ich

th

e r

oo

ts l

ie.

5.

p2

14p

12 5

06.

x2

1x

23 5

0

24 ,

p,

23,

21 ,

p,

02

3 ,

x,

22,1 ,

x,

2

7.

d2

16

d5

23

8.

h2

11 5

4h

26 ,

d,

25,

21 ,

d,

00 ,

h,

1,3 ,

h,

4

hO

f(h)

dO

f(d

)

xO

f(x)

pO

f(p)

nO

f(n)

a

f (a)

O

cO

f(c)

xO

f(x)

©G

lencoe/M

cG

raw

-Hill

588

Gle

ncoe A

lgebra

1

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.

1.

x2

25x

16 5

02,3

2.

w2

16

w1

9 5

02

33.

b2

24

b1

5 5

0[

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

.If

in

teg

ra

l ro

ots

ca

nn

ot

be f

ou

nd

,est

ima

te t

he

ro

ots

by

sta

tin

g t

he c

on

secu

tiv

e i

nte

gers

betw

een

wh

ich

th

e r

oo

ts l

ie.

4.

p2

14p

53

5.

2m

21

5 5

10m

6.

2v

21

8v

52

7

25 ,

p,

24,

0 ,

m,

1,

23 ,

v,

22,

0 ,

p,

14 ,

m,

52

2 ,

v,

21

NU

MB

ER

TH

EO

RY

Fo

r E

xercis

es

7 a

nd

8,

use

th

e

foll

ow

ing

in

form

ati

on

.

Tw

o n

um

ber

s h

ave

a s

um

of

2 a

nd

a p

rod

uct

of

28.T

he

qu

ad

rati

c eq

uati

on 2

n2

12n

18 5

0 c

an

be

use

d t

o d

eter

min

e th

e tw

o n

um

ber

s.

7.

Gra

ph

th

e re

late

d f

un

ctio

n f

(n)

52

n2

12n

18 a

nd

d

eter

min

e it

s x-i

nte

rcep

ts.

22,4

8.

Wh

at

are

th

e tw

o n

um

ber

s?2

2 a

nd

4

DE

SIG

NF

or E

xercis

es

9 a

nd

10,

use

th

e f

oll

ow

ing

in

form

ati

on

.

A f

ootb

rid

ge

is s

usp

end

ed f

rom

a p

ara

bol

ic s

up

por

t.T

he

fun

ctio

n

h(x

) 5

2x

21

9 r

epre

sen

ts t

he

hei

gh

t in

fee

t of

th

e su

pp

ort

abov

e

the

walk

way,

wh

ere

x5

0 r

epre

sen

ts t

he

mid

poi

nt

of t

he

bri

dge.

9.

Gra

ph

th

e fu

nct

ion

an

d d

eter

min

e it

s x-i

nte

rcep

ts.

215,15

10.W

hat

is t

he

len

gth

of

the

walk

way b

etw

een

th

e tw

o su

pp

orts

?30 f

t

1} 2

5x

h (x)

O6

12

12 6

26

212

212

26

n

f (n)

O

v

f(v)

O

m

f (m

)

Op

O

f(p)

b

f (b)

O

w

f (w

)

Ox

O

f(x)Pra

cti

ce (

Avera

ge)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y G

rap

hin

g

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

Answers (Lesson 10-2)

Page 6: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A7 Glencoe Algebra 1

An

swers

Readin

g t

o L

earn

Math

em

ati

cs

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y G

rap

hin

g

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

©G

lencoe/M

cG

raw

-Hill

589

Gle

ncoe A

lgebra

1

Lesson 10-2

Pre

-Act

ivit

yH

ow

ca

n q

ua

dra

tic e

qu

ati

on

s b

e u

sed

in

co

mp

ute

r s

imu

lati

on

s?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-2

at

the

top

of

page

533 i

n y

our

textb

ook

.

If o

ne

of t

he

x-i

nte

rcep

ts r

epre

sen

ts t

he

loca

tion

wh

ere

the

ball

wil

l h

it t

he

gro

un

d,w

hat

doe

s th

e ot

her

x-i

nte

rcep

t re

pre

sen

t?T

he l

ocati

on

wh

ere

the b

all i

s h

it.

Read

ing

th

e L

ess

on

1.

Th

e x-i

nte

rcep

ts o

f th

e gra

ph

of

a q

uad

rati

c fu

nct

ion

are

th

e x-c

oord

inate

s of

th

e p

oin

tsw

her

e th

e gra

ph

of

the

fun

ctio

n i

nte

rsec

ts t

he

x-a

xis

.A

t th

ose

poi

nts

,th

e y-c

oord

inate

s

are

equ

al

to

.T

his

exp

lain

s w

hy t

he

x-i

nte

rcep

ts a

re c

all

ed

of t

he

qu

ad

rati

c fu

nct

ion

.

2.

Th

e gra

ph

s of

th

ree

fun

ctio

ns

are

sh

own

bel

ow.U

se t

he

gra

ph

s to

pro

vid

e th

e re

qu

este

din

form

ati

on a

bou

t th

e re

late

d q

uad

rati

c eq

uati

ons.

A.

f(x)

5x

22

6x

19

B.

f(x)

5x

21

2x

13

C.

f(x)

5x

21

x2

2

a.

For

Gra

ph

A,th

e re

late

d q

uad

rati

c eq

uati

on i

s .

How

man

y s

olu

tion

s are

th

ere?

on

e

Nam

e an

y s

olu

tion

s.3

b.

For

Gra

ph

B,th

e re

late

d q

uad

rati

c eq

uati

on i

s .

How

man

y s

olu

tion

s are

th

ere?

no

ne

Nam

e an

y s

olu

tion

s.n

on

e

c.

For

Gra

ph

C,th

e re

late

d q

uad

rati

c eq

uati

on i

s .

How

man

y s

olu

tion

s are

th

ere?

two

Nam

e an

y s

olu

tion

s.2

2 a

nd

1

Help

ing

Yo

u R

em

em

ber

3.

Des

crib

e h

ow y

ou c

an

rem

ember

th

at

the

wor

d z

ero

is u

sed

wh

en y

ou a

re t

alk

ing a

bou

tfu

nct

ion

s,bu

t th

e w

ord

root

is u

sed

wh

en y

ou a

re t

alk

ing a

bou

t eq

uati

ons.

Sam

ple

an

sw

er:

So

me f

un

cti

on

s c

an

have a

valu

e o

f zero

.E

qu

ati

on

s c

an

be t

rue

or

fals

e,b

ut

they d

o n

ot

have a

nu

mb

er

valu

e.x

21

x2

2 5

0

x2

12

x1

3 5

0

x2

26

x1

9 5

0

xO

f(x)

xO

f(x)

xO

f(x)

ze

ros

0

©G

lencoe/M

cG

raw

-Hill

590

Gle

ncoe A

lgebra

1

Od

d N

um

bers

an

d P

ara

bo

las

Th

e so

lid

para

bol

a a

nd

th

e d

ash

ed s

tair

-ste

p g

rap

h a

re

rela

ted

.T

he

para

bol

a i

nte

rsec

ts t

he

stair

ste

ps

at

thei

r in

sid

e co

rner

s.

Use

th

e f

igu

re f

or E

xercis

es

1–3.

1.

Wh

at

is t

he

equ

ati

on o

f th

e p

ara

bol

a?

y5

x2

2.

Des

crib

e th

e h

oriz

onta

l se

ctio

ns

of t

he

stair

-ste

p g

rap

h.

Each

is 1

un

it w

ide

.

3.

Des

crib

e th

e ver

tica

l se

ctio

ns

of t

he

stair

-ste

p g

rap

h.

Th

ey f

orm

th

e s

eq

uen

ce 1

,3,5,7.

Use

th

e s

eco

nd

fig

ure f

or E

xercis

es

4–6.

4.

Wh

at

is t

he

equ

ati

on o

f th

e p

ara

bol

a?

y5

x2

5.

Des

crib

e th

e h

oriz

onta

l se

ctio

ns

of t

he

stair

ste

ps.

Each

is 1

un

it w

ide

.

6.

Des

crib

e th

e ver

tica

l se

ctio

ns.

Th

ey f

orm

th

e s

eq

uen

ce

,,

,,

.

7.

How

doe

s th

e gra

ph

of

y5

x2

rela

te t

o th

e se

qu

ence

of

nu

mber

s ,

,,

,…

?

If t

he x

valu

es i

ncre

ase b

y 1

,th

e y

valu

es i

ncre

ase b

y t

he n

um

bers

in

th

e s

eq

uen

ce

.

8.

Com

ple

te t

his

con

clu

sion

.T

o gra

ph

a p

ara

bol

a w

ith

th

e eq

uati

on y

5a

x2,st

art

at

the

ver

tex.T

hen

go

over

1 a

nd

up

a;ov

er 1

an

d u

p 3

a;

over

1 a

nd

up

5a;

over

1 a

nd

up

7a

;an

d s

o o

n.T

he c

oeff

icie

nts

of

aare

the o

dd

nu

mb

ers

.

7 } 2

5 } 2

3 } 2

1 } 2

1 } 2

9 } 27 } 2

5 } 23 } 2

1 } 2

1 } 2

x

y O

x

y O

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-2

10-2

Answers (Lesson 10-2)

Page 7: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A8 Glencoe Algebra 1

Stu

dy G

uid

e a

nd I

nte

rven

tion

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y C

om

ple

tin

g t

he S

qu

are

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

©G

lencoe/M

cG

raw

-Hill

591

Gle

ncoe A

lgebra

1

Lesson 10-3

Fin

d t

he S

qu

are

Ro

ot

An

equ

ati

on s

uch

as

x2

24x

14 5

5 c

an

be

solv

ed b

y t

ak

ing

the

squ

are

roo

t of

each

sid

e.

So

lve x

22

2x

11 5

9.

Ro

un

d t

o t

he n

ea

rest

ten

th i

fn

ecess

ary.

x2

22

x1

1 5

9

(x2

1)2

59

Ï(x

21

w)2 w

9w|x

21

|5Ï

9wx

21 5

63

x2

1 1

1 5

63 1

1

x5

1 6

3

x5

1 1

3or

x5

1 2

3

54

52

2

Th

e so

luti

on s

et i

s {2

2,4}.

So

lve x

22

4x

14 5

5.

Ro

un

d t

o t

he n

ea

rest

ten

th i

fn

ecess

ary.

x2

24x

14 5

5

(x2

2)2

55

Ï(x

22

w)2 w

5w|x

22

|5

Ï5w

x2

2 5

5wx

22 1

2 5

5w1

2

x5

2 6

Ï5w

Use

a c

alc

ula

tor

to e

valu

ate

each

valu

e of

x.

x5

2 1

Ï5w

orx

52 2

Ï5w

<4.2

<2

0.2

Th

e so

luti

on s

et i

s {2

0.2

,4.2

}.

Example

1Example

1Example

2Example

2

Exercises

Exercises

So

lve e

ach

eq

ua

tio

n b

y t

ak

ing

th

e s

qu

are r

oo

t o

f ea

ch

sid

e.

Ro

un

d t

o t

he n

ea

rest

ten

th i

f n

ecess

ary.

1.

x2

14x

14 5

92.

m2

112m

136 5

13.

r22

6r

19 5

16

25,1

27,

25

21,7

4.

x2

22x

11 5

25

5.

x2

28

x1

16 5

56.

x2

210x

125 5

8

24,6

1.8

,6.2

2.2

,7.8

7.

c22

4c

14 5

78.

p2

116p

164 5

39.

x2

18

x1

16 5

9

20.6

,4.6

29.7

,2

6.3

27,

21

10.x

21

6x

19 5

411.

a2

18a

116 5

10

12.

y2

212y

136 5

5

25,

21

27.2

,2

0.8

3.8

,8.2

13.x

21

10x

125 5

114.

y2

114y

149 5

615.

m2

28m

116 5

2

26,

24

29.4

,2

4.6

2.6

,5.4

16.x

21

12x

136 5

10

17.

a2

214a

149 5

318.

y2

18

y1

16 5

7

29.2

,2

2.8

5.3

,8.7

26.6

,2

1.4

©G

lencoe/M

cG

raw

-Hill

592

Gle

ncoe A

lgebra

1

Co

mp

lete

th

e S

qu

are

Sin

ce f

ew q

uad

rati

c ex

pre

ssio

ns

are

per

fect

squ

are

tri

nom

ials

,th

e m

eth

od o

f co

mp

leti

ng

th

e s

qu

are

can

be

use

d t

o so

lve

som

e qu

ad

rati

c eq

uati

ons.

Use

the

foll

owin

g s

tep

s to

com

ple

te t

he

squ

are

for

a q

uad

rati

c ex

pre

ssio

n o

f th

e fo

rm a

x2

1bx.

Ste

p 1

Fin

d

.

Ste

p 2

Fin

d 1

22.

Ste

p 3

Add 1

22to

ax

21

bx.

So

lve x

21

6x

13 5

10 b

y c

om

ple

tin

g t

he s

qu

are.

x2

16x

13 5

10

Origin

al equation

x2

16

x1

3 2

3 5

10 2

3S

ubtr

act

3 f

rom

each s

ide.

x2

16x

57

Sim

plif

y.

x2

16x

19 5

7 1

9S

ince 1

225

9,

add 9

to e

ach s

ide.

(x1

3)2

516

Facto

r x

21

6x

19.

x1

3 5

64

Take t

he s

quare

root

of

each s

ide.

x5

23 6

4S

implif

y.

x5

23 1

4or

x5

23 2

4

51

52

7

Th

e so

luti

on s

et i

s {2

7,1}.

So

lve e

ach

eq

ua

tio

n b

y c

om

ple

tin

g t

he s

qu

are.

Ro

un

d t

o t

he n

ea

rest

ten

th i

fn

ecess

ary.

1.

t22

4t

13 5

02.

y2

110y

52

93.

y2

28y

29 5

0

1,3

21,

29

21,9

4.

x2

26x

516

5.

p2

24p

25 5

06.

x2

212x

59

22,8

21,5

20.7

,12.7

7.

c21

8c

520

8.

p2

52p

11

9.

x2

120x

111 5

28

210,2

20.4

,2.4

219,

21

10.x

22

1 5

5x

11.

a2

522a

123

12.

m2

28

m5

27

20.2

,5.2

21,23

1,7

13.x

21

10x

524

14.

a2

218a

519

15.

b2

116b

52

16

212,2

21,19

214.9

,2

1.1

16.4x

25

24 1

4x

17.

2m

21

4m

12 5

818.

4k

25

40k

144

22,3

23,1

21,11

6 } 2

b } 2b } 2b } 2

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y C

om

ple

tin

g t

he S

qu

are

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

Example

Example

Exercises

Exercises

Answers (Lesson 10-3)

Page 8: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A9 Glencoe Algebra 1

An

swers

Skil

ls P

racti

ce

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y C

om

ple

tin

g t

he S

qu

are

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

©G

lencoe/M

cG

raw

-Hill

593

Gle

ncoe A

lgebra

1

Lesson 10-3

So

lve e

ach

eq

ua

tio

n b

y t

ak

ing

th

e s

qu

are r

oo

t o

f ea

ch

sid

e.

Ro

un

d t

o t

he n

ea

rest

ten

th i

f n

ecess

ary.

1.

c22

12c

136 5

44,8

2.

w2

210w

125 5

16

1,9

3.

b2

116b

164 5

92

11,

25

4.

y2

12

y1

1 5

32

2.7

,0.7

5.

r21

4r

14 5

72

4.6

,0.6

6.

a2

28a

116 5

12

0.5

,7.5

Fin

d t

he v

alu

e o

f c

tha

t m

ak

es

ea

ch

trin

om

ial

a p

erfe

ct

squ

are.

7.

g2

16

g1

c9

8.

y2

14

y1

c4

9.

a2

214a

1c

49

10.

n2

22

n1

c1

11.s2

218s

1c

81

12.

p2

120p

1c

10

0

So

lve e

ach

eq

ua

tio

n b

y c

om

ple

tin

g t

he s

qu

are.

Ro

un

d t

o t

he n

ea

rest

ten

th i

fn

ecess

ary.

13.x

21

4x

212 5

02,

26

14.

v2

28v

115 5

03,5

15.q

21

6q

57

27,1

16.

r22

2r

515

23,5

17.m

22

14m

130 5

62,12

18.

b2

112b

121 5

10

211,

21

19.z2

24z

11 5

00.3

,3.7

20.

y2

26

y1

4 5

00.8

,5.2

21.r2

28r

110 5

01.6

,6.4

22.

p2

22p

55

21.4

,3.4

23.2a

21

20a

52

22

9.9

,2

0.1

24.

0.5

g2

18g

52

72

15.1

,2

0.9

©G

lencoe/M

cG

raw

-Hill

594

Gle

ncoe A

lgebra

1

So

lve e

ach

eq

ua

tio

n b

y t

ak

ing

th

e s

qu

are r

oo

t o

f ea

ch

sid

e.

Ro

un

d t

o t

he n

ea

rest

ten

th i

f n

ecess

ary.

1.

b2

214b

149 5

64

2.

s21

16s

164 5

100

3.

h2

28

h1

16 5

15

21,15

218,2

0.1

,7.9

4.

a2

16a

19 5

27

5.

p2

220p

1100 5

28

6.

u2

110u

125 5

90

28.2

,2.2

4.7

,15.3

214.5

,4.5

Fin

d t

he v

alu

e o

f c

tha

t m

ak

es

ea

ch

trin

om

ial

a p

erfe

ct

squ

are.

7.

t22

24t

1c

14

48.

b2

128b

1c

19

69.

y2

140y

1c

40

0

10.m

21

3m

1c

11.

g2

29

g1

c12.

v2

2v

1c

So

lve e

ach

eq

ua

tio

n b

y c

om

ple

tin

g t

he s

qu

are.

Ro

un

d t

o t

he n

ea

rest

ten

th i

fn

ecess

ary.

13.w

22

14w

124 5

014.

p2

112p

513

15.

s22

30s

156 5

225

2,12

213,1

3,27

16.v

21

8v

19 5

017.

t22

10t

16 5

27

18.

n2

118n

150 5

9

26.6

,2

1.4

1.5

,8.5

215.3

,2

2.7

19.3u

21

15u

23 5

020.

4c2

272 5

24c

21.

0.9

a2

15.4

a2

4 5

0

25.2

,0.2

22.2

,8.2

26

,

22.0.4

h2

10.8

h5

0.2

23.

x2

2x

210 5

024.

x2

1x

22 5

0

22.2

,0.2

24,5

27.1

,1.1

BU

SIN

ES

SF

or E

xercis

es

25 a

nd

26,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Jaim

e ow

ns

a b

usi

nes

s m

ak

ing d

ecor

ati

ve

box

es t

o st

ore

jew

elry

,m

emen

tos,

an

d o

ther

valu

able

s.T

he

fun

ctio

n y

5x

21

50x

11800 m

odel

s th

e p

rofi

t y

that

Jaim

e h

as

mad

e in

mon

th x

for

the

firs

t tw

o yea

rs o

f h

is b

usi

nes

s.

25.W

rite

an

equ

ati

on r

epre

sen

tin

g t

he

mon

th i

n w

hic

h J

aim

e’s

pro

fit

is $

2400.

x2

15

0x

11800 5

24

00

26.U

se c

omp

leti

ng t

he

squ

are

to

fin

d o

ut

in w

hic

h m

onth

Jaim

e’s

pro

fit

is $

2400.

the t

en

th m

on

th

27.P

HY

SIC

SF

rom

a h

eigh

t of

256 f

eet

abov

e a l

ak

e on

a c

liff

,M

ikael

a t

hro

ws

a r

ock

ou

tov

er t

he

lak

e.T

he

hei

gh

t H

of t

he

rock

tse

con

ds

aft

er M

ikael

a t

hro

ws

it i

s re

pre

sen

ted

by t

he

equ

ati

on H

52

16t2

132t

1256.T

o th

e n

eare

st t

enth

of

a s

econ

d,h

ow l

ong d

oes

it t

ak

e th

e ro

ck t

o re

ach

th

e la

ke

bel

ow?

(Hin

t:R

epla

ce H

wit

h 0

.)5.1

s3 } 21 } 4

1 } 21 } 2

2 } 32 } 3

1 } 481

} 49 } 4

Pra

cti

ce (

Avera

ge)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y C

om

ple

tin

g t

he S

qu

are

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

Answers (Lesson 10-3)

Page 9: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A10 Glencoe Algebra 1

Readin

g t

o L

earn

Math

em

ati

cs

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y C

om

ple

tin

g t

he S

qu

are

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

©G

lencoe/M

cG

raw

-Hill

595

Gle

ncoe A

lgebra

1

Lesson 10-3

Pre

-Act

ivit

yH

ow

did

an

cie

nt

ma

them

ati

cia

ns

use

sq

ua

res

to s

olv

e a

lgeb

ra

iceq

ua

tio

ns?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-3

at

the

top

of

page

539 i

n y

our

textb

ook

.

To

solv

e th

e p

roble

m,h

ow m

an

y “

un

its”

wou

ld A

l-K

hw

ari

zmi

have

ad

ded

to

each

sid

e of

th

e eq

uati

on?

16

Read

ing

th

e L

ess

on

1.

Dra

w a

lin

e u

nd

er e

ach

qu

ad

rati

c eq

uati

on t

hat

you

cou

ld s

olve

by t

ak

ing t

he

squ

are

root

of

each

sid

e.

x2

16x

19 5

100

x2

214x

140 5

25

x2

216x

164 5

26

x2

220x

180 5

16

x2

110x

136 5

49

x2

212x

136 5

6

2.

How

can

you

tel

l w

het

her

it

is p

ossi

ble

to

solv

e a q

uad

rati

c eq

uati

on b

y t

ak

ing t

he

squ

are

roo

t of

each

sid

e?

Sam

ple

an

sw

er:

Ch

eck t

o b

e s

ure

th

at

all t

erm

s t

hat

co

nta

in t

he v

ari

ab

leare

on

th

e s

am

e s

ide o

f th

e e

qu

ati

on

.N

ext,

ch

eck w

heth

er

the q

uad

rati

cexp

ressio

n i

s a

perf

ect

sq

uare

.F

inally,

ch

eck t

hat

the n

um

ber

on

th

e s

ide

that

co

nta

ins n

o v

ari

ab

les i

s g

reate

r th

an

or

eq

ual

to 0

.

3.

Exp

lain

how

to

fin

d w

hat

nu

mber

is

nee

ded

for

th

e n

in o

rder

to

mak

e x

22

20x

1n

a p

erfe

ct s

qu

are

.

Fin

d o

ne h

alf

of

220,w

hic

h i

s 2

10,an

d s

qu

are

it.

Th

e r

esu

lt,w

hic

h i

s100,is

th

e r

eq

uir

ed

nu

mb

er.

4.

To

solv

e 3x

22

6x

554 b

y c

omp

leti

ng t

he

squ

are

,w

hy d

oes

it h

elp

fir

st t

o d

ivid

e bot

hsi

des

by 3

?

Sam

ple

an

sw

er:

If y

ou

div

ide b

oth

sid

es b

y 3

,th

e c

oeff

icie

nt

of

x2

will

be

1.It

is t

hen

easy t

o u

se t

he c

oeff

icie

nt

of

xto

decid

e w

hat

nu

mb

er

yo

un

eed

to

ad

d t

o b

oth

sid

es t

o m

ake t

he l

eft

sid

e a

perf

ect

sq

uare

trin

om

ial.

Help

ing

Yo

u R

em

em

ber

5.

Th

e m

eth

od o

f co

mp

leti

ng t

he

squ

are

mig

ht

be

easi

er t

o re

mem

ber

if

you

can

con

nec

t it

to w

hat

you

kn

ow a

bou

t p

erfe

ct s

qu

are

tri

nom

ials

.H

ow i

s co

mp

leti

ng t

he

squ

are

rel

ate

dto

th

e m

eth

od y

ou u

se t

o d

eter

min

e w

het

her

a t

rin

omia

l is

a p

erfe

ct s

qu

are

tri

nom

ial?

Sam

ple

an

sw

er:

If t

he f

irst

an

d l

ast

term

s o

f a t

rin

om

ial

are

perf

ect

sq

uare

s,yo

u m

ult

iply

the p

rod

uct

of

their

sq

uare

ro

ots

by 2

to g

et

the

mid

dle

term

.In

co

mp

leti

ng

th

e s

qu

are

,yo

u c

heck t

hat

the c

oeff

icie

nt

of

x2

is 1

.Th

en

yo

u d

ivid

e t

he c

oeff

icie

nt

of

the x

term

by 2

an

d s

qu

are

th

ere

su

lt t

o g

et

the t

hir

d t

erm

.

©G

lencoe/M

cG

raw

-Hill

596

Gle

ncoe A

lgebra

1

Para

bo

las T

hro

ug

h T

hre

e G

iven

Po

ints

If y

ou k

now

tw

o p

oin

ts o

n a

str

aig

ht

lin

e,you

can

fin

d t

he

equ

ati

on o

fth

e li

ne.

To

fin

d t

he

equ

ati

on o

f a p

ara

bol

a,you

nee

d t

hre

e p

oin

ts o

nth

e cu

rve.

Her

e is

how

to

ap

pro

xim

ate

an

equ

ati

on o

f th

e p

ara

bol

a t

hro

ugh

th

ep

oin

ts (

0,

22),

(3,0),

an

d (

5,2).

Use

th

e gen

eral

equ

ati

on y

5a

x2

1bx

1c.

By s

ubst

itu

tin

g t

he

giv

envalu

es f

or x

an

d y

,you

get

th

ree

equ

ati

ons.

(0,

22):

22 5

c

(3,0):

0 5

9a

13

b1

c

(5,2):

2 5

25a

15b

1c

Fir

st,su

bst

itu

te 2

2 f

or c

in t

he

seco

nd

an

d t

hir

d e

qu

ati

ons.

Th

enso

lve

thos

e tw

o eq

uati

ons

as

you

wou

ld a

ny s

yst

em o

f tw

o eq

uati

ons.

Mu

ltip

ly t

he

seco

nd

equ

ati

on b

y 5

an

d t

he

thir

d e

qu

ati

on b

y 2

3.

0 5

9a

13b

22

Multip

ly b

y 5

.0 5

45a

115b

210

0 5

25a

15

b2

2M

ultip

ly b

y 2

3.

26 5

275a

215b

16

26 5

230a

215b

24

a5

To

fin

d b

,su

bst

itu

te

for

ain

eit

her

th

e se

con

d o

r th

ird

equ

ati

on.

0 5

91

213b

22

b5

Th

e eq

uati

on o

f a p

ara

bol

a t

hro

ugh

th

e th

ree

poi

nts

is

y5

x2

1x

22.

Fin

d t

he e

qu

ati

on

of

a p

ara

bo

la t

hro

ug

h e

ach

set

of

three p

oin

ts.

1.

(1,5),

(0,6),

(2,3)

2.

(25,0),

(0,0),

(8,100)

y5

2x

22

x1

6y

5x

21

x

3.

(4,

24),

(0,1),

(3,

22)

4.

(1,3),

(6,0),

(0,0)

y5

2x

22

x1

6y

52

x2

1x

5.

(2,2),

(5,

23),

(0,

21)

6.

(0,4),

(4,0),

(24,4)

y5

2x

21

x2

1y

52

x2

2x

14

1 } 21 } 8

83

} 30

19

} 30

18

} 53 } 5

1 } 41 } 4

125

} 26

25

} 26

1 } 21 } 2

7} 1

5

1} 1

57} 1

5

1} 1

5

1} 1

5

1} 1

5

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-3

10-3

Answers (Lesson 10-3)

Page 10: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A11 Glencoe Algebra 1

An

swers

Stu

dy G

uid

e a

nd I

nte

rven

tion

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y U

sin

g t

he Q

uad

rati

c F

orm

ula

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

©G

lencoe/M

cG

raw

-Hill

597

Gle

ncoe A

lgebra

1

Lesson 10-4

Qu

ad

rati

c Fo

rmu

laT

o so

lve

the

stan

dard

for

m o

f th

e qu

ad

rati

c eq

uati

on,

ax

21

bx

1c

50,u

se t

he

Qu

ad

ra

tic F

orm

ula

.

Qu

ad

rati

c F

orm

ula

the f

orm

ula

x5

that

giv

es t

he s

olu

tions o

f ax

21

bx

1c

50,

where

02

b6

Ïb

22

w4a

cw

}}

}2

a

So

lve x

21

2x

53 b

yu

sin

g t

he Q

ua

dra

tic F

orm

ula

.

Rew

rite

th

e eq

uati

on i

n s

tan

dard

for

m.

x2

12x

53

Origin

al equation

x2

12

x2

3 5

3 2

3S

ubtr

act

3 f

rom

each s

ide.

x2

12

x2

3 5

0S

implif

y.

Now

let

a5

1,b

52,an

d c

52

3 i

n t

he

Qu

ad

rati

c F

orm

ula

.

x5 5 5

x5

orx

5

51

52

3T

he

solu

tion

set

is

{23,1}.

22 2

4}

22

2 1

4}

2

22 6

Ï16w

}} 2

22 6

Ï(2

)22

w4(1

)(2

w3)w

}}

}2(1

)

2b

b2

24

wa

cw}

}}

2a

So

lve x

22

6x

22 5

0 b

yu

sin

g t

he Q

ua

dra

tic F

orm

ula

.R

ou

nd

to

the n

ea

rest

ten

th i

f n

ecess

ary.

For

th

is e

qu

ati

on a

51,b

52

6,an

d c

52

2.

x5 5 5

x5

orx

5

<6.3

<2

0.3

Th

e so

luti

on s

et i

s {2

0.3

,6.3

}.

6 2

Ï44w

}} 2

6 1

Ï44w

}} 2

6 6

Ï44w

}} 2

6 6

Ï(2

6)2

w2

4(1

w)(

22)

w}

}}

2(1

)

2b

b2

24

wa

cw}

}}

2a

Example

1Example

1Example

2Example

2

Exercises

Exercises

So

lve e

ach

eq

ua

tio

n b

y u

sin

g t

he Q

ua

dra

tic F

orm

ula

.R

ou

nd

to

th

e n

ea

rest

ten

thif

necess

ary.

1.

x2

23x

12 5

01,2

2.

m2

28

m5

216

43.

16r2

28

r5

21

4.

x2

15x

56

26,1

5.

3x

21

2x

58

22,

6.

8x

22

8x

25 5

02

0.4

,1.4

7.

24

c21

19c

521

,3

8.

2p

21

6p

55

23.7

,0.7

9.

48x

21

22x

215 5

02

,

10.8x

22

4x

524

2,2

11.

2p

21

5p

58

23.6

,1.1

12.

8y

21

9y

24 5

02

1.5

,0.3

13.2x

21

9x

14 5

02

4,

214.

8y

21

17y

12 5

02

2,

2

15.3z2

15

z2

2 5

02

2,

16.

22

x2

18x

14 5

02

0.4

,4.4

17.a

21

3a

52

23.6

,0.6

18.

2y

22

6y

14 5

01,2

1 } 3

1 } 81 } 2

3 } 2

3 } 85 } 6

7 } 4

4 } 3

1 } 4

©G

lencoe/M

cG

raw

-Hill

598

Gle

ncoe A

lgebra

1

Th

e D

iscr

imin

an

tIn

th

e Q

uad

rati

c F

orm

ula

,x

5,th

e ex

pre

ssio

n u

nd

er

the

rad

ical

sign

,b

22

4a

c,is

call

ed t

he

dis

crim

ina

nt.

Th

e d

iscr

imin

an

t ca

n b

e u

sed

to

det

erm

ine

the

nu

mber

of

real

root

s fo

r a q

uad

rati

c eq

uati

on.

Case 1

:C

ase 2

:C

ase 3

:

b2

24

ac

,0

b2

24

ac

50

b2

24

ac

.0

no r

eal ro

ots

one r

eal ro

ot

two r

eal ro

ots

Sta

te t

he v

alu

e o

f th

e d

iscrim

ina

nt

for e

ach

eq

ua

tio

n.T

hen

dete

rm

ine t

he n

um

ber o

f rea

l ro

ots

.

2b

b2

24

wa

cw}

}}

2a

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y U

sin

g t

he Q

uad

rati

c F

orm

ula

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

Example

Example

a.

12x

21

5x

54

Wri

te t

he

equ

ati

on i

n s

tan

dard

for

m.

12x

21

5x

54

Origin

al equation

12x

21

5x

24 5

4 2

4S

ubtr

act

4 f

rom

each s

ide.

12x

21

5x

24 5

0S

implif

y.

Now

fin

d t

he

dis

crim

inan

t.

b2

24a

c5

(5)2

24(1

2)(

24)

5217

Sin

ce t

he

dis

crim

inan

t is

pos

itiv

e,th

eeq

uati

on h

as

two

real

root

s.

b.

2x

21

3x

52

4

2x

21

3x

52

4O

rigin

al equation

2x

21

3x

14 5

24 1

4A

dd 4

to e

ach s

ide.

2x

21

3x

14 5

0S

implif

y.

b2

24

ac

5(3

)22

4(2

)(4)

52

23

Sin

ce t

he

dis

crim

inan

t is

neg

ati

ve,

the

equ

ati

on h

as

no

real

root

s.

Exercises

Exercises

Sta

te t

he v

alu

e o

f th

e d

iscrim

ina

nt

for e

ach

eq

ua

tio

n.T

hen

dete

rm

ine t

he n

um

ber

of

rea

l ro

ots

of

the e

qu

ati

on

.

1.

3x

21

2x

23 5

02.

3n

22

7n

28 5

03.

2d

22

10d

29 5

0

40,2 r

eal

roo

ts145,2 r

eal

roo

ts172,2 r

eal

roo

ts

4.

4x

25

x1

45.

3x

22

13x

510

6.

6x

22

10x

110 5

0

65,2 r

eal

roo

ts289,2 r

eal

roo

ts2

140,n

o r

eal

roo

ts

7.

2k

22

20 5

2k

8.

6p

25

211p

240

9.

9 2

18x

19

x2

50

161,2 r

eal

roo

ts2

839,n

o r

eal

roo

ts0,1 r

eal

roo

t

10.12x

21

9 5

26

x11.

9a

25

81

12.

16y

21

16y

14 5

0

2396,n

o r

eal

roo

ts2916,2 r

eal

roo

ts0,1 r

eal

roo

ts

13.8

x2

19

x5

214.

4a

22

4a

14 5

315.

3b

22

18b

52

14

145,2 r

eal

roo

ts0,1 r

eal

roo

t156,2 r

eal

roo

ts

Answers (Lesson 10-4)

Page 11: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A12 Glencoe Algebra 1

Skil

ls P

racti

ce

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y U

sin

g t

he Q

uad

rati

c F

orm

ula

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

©G

lencoe/M

cG

raw

-Hill

599

Gle

ncoe A

lgebra

1

Lesson 10-4

So

lve e

ach

eq

ua

tio

n b

y u

sin

g t

he Q

ua

dra

tic F

orm

ula

.R

ou

nd

to

th

e n

ea

rest

ten

thif

necess

ary.

1.

u2

249 5

02

7,7

2.

n2

2n

220 5

02

4,5

3.

s22

5s

236 5

02

4,9

4.

b2

111b

130 5

02

6,

25

5.

c22

7c

52

30.5

,6.5

6.

p2

14p

52

12

3.7

,2

0.3

7.

a2

29a

122 5

0[

8.

x2

16

x1

3 5

02

5.4

,2

0.6

9.

2x

21

5x

27 5

02

3,1

10.

2h

22

3h

52

1,1

11.2p

21

5p

14 5

0[

12.

2g

21

7g

59

24

,1

13.3t2

12

t2

3 5

02

1.4

,0.7

14.

3x

22

7x

26 5

02

,3

Sta

te t

he v

alu

e o

f th

e d

iscrim

ina

nt

for e

ach

eq

ua

tio

n.T

hen

dete

rm

ine t

he n

um

ber

of

rea

l ro

ots

of

the e

qu

ati

on

.

15.q

21

4q

13 5

016.

m2

12

m1

1 5

0

4;

2 r

eal

roo

ts0;

1 r

eal

roo

t

17.a

22

4a

110 5

018.

w2

26

w1

7 5

0

224;

no

real

roo

ts8;

2 r

eal

roo

ts

19.z2

22z

27 5

020.

y2

210y

125 5

0

32;

2 r

eal

roo

ts0;

1 r

eal

roo

t

21.2d

21

5d

28 5

022.

2s2

16s

112 5

0

89;

2 r

eal

roo

ts2

60;

no

real

roo

ts

23.2u

22

4u

110 5

024.

3h

21

7h

13 5

0

264;

no

real

roo

ts13;

2 r

eal

roo

ts

2 } 3

1 } 2

1 } 21 } 2

©G

lencoe/M

cG

raw

-Hill

600

Gle

ncoe A

lgebra

1

So

lve e

ach

eq

ua

tio

n b

y u

sin

g t

he Q

ua

dra

tic F

orm

ula

.R

ou

nd

to

th

e n

ea

rest

ten

thif

necess

ary.

1.

g2

12

g2

3 5

02

3,1

2.

a2

18a

17 5

02

7,

21

3.

v2

24v

16 5

0[

4.

d2

26

d1

7 5

01.6

,4.4

5.

2z2

19

z2

5 5

02

5,

6.

2r2

112r

110 5

025,

21

7.

2b

22

9b

52

12

[8.

2h

22

5h

512

21

,4

9.

3p

21

p5

42

1,1

10.3m

22

1 5

28

m22.8

,0.1

11.

4y

21

7y

515

23,1

12.

1.6

n2

12

n1

2.5

50

[

13.4.5

k2

14

k2

1.5

50

14.

c21

2c

15

015.

3w

22

w5

21.2

,0.3

23,

21

20.3

,0.6

Sta

te t

he v

alu

e o

f th

e d

iscrim

ina

nt

for e

ach

eq

ua

tio

n.T

hen

dete

rm

ine t

he n

um

ber

of

rea

l ro

ots

of

the e

qu

ati

on

.

16.a

21

8a

116 5

017.

c21

3c

112 5

018.

2w

21

12w

52

7

0;

1 r

eal

roo

t2

39;

no

real

roo

ts88;

2 r

eal

roo

ts

19.2u

21

15u

52

30

20.

4n

21

9 5

12n

21.

3g

22

2g

53.5

215;

no

real

roo

ts0;

1 r

eal

roo

t46;

2 r

eal

roo

ts

22.2.5

k2

13

k2

0.5

50

23.

d2

23

d5

24

24.

s25

2s

21

14;

2 r

eal

roo

ts2

3;

no

real

roo

ts0;

1 r

eal

roo

t

CO

NS

TR

UC

TIO

NF

or E

xercis

es

25 a

nd

26,

use

th

e f

oll

ow

ing

in

form

ati

on

.

A r

oofe

r to

sses

a p

iece

of

roof

ing t

ile

from

a r

oof

onto

th

e gro

un

d 3

0 f

eet

bel

ow.H

e to

sses

th

eti

le w

ith

an

in

itia

l d

own

ward

vel

ocit

y o

f 10 f

eet

per

sec

ond

.

25.W

rite

an

equ

ati

on t

o fi

nd

how

lon

g i

t ta

kes

th

e ti

le t

o h

it t

he

gro

un

d.U

se t

he

mod

el f

orver

tica

l m

otio

n,H

52

16t2

1vt

1h

,w

her

e H

is t

he

hei

gh

t of

an

obje

ct a

fter

tse

con

ds,

vis

th

e in

itia

l vel

ocit

y,an

d h

is t

he

init

ial

hei

gh

t.(H

int:

Sin

ce t

he

obje

ct i

s th

row

n d

own

,th

e in

itia

l vel

ocit

y i

s n

egati

ve.

)H

52

16

t22

10

t1

30

26.H

ow l

ong d

oes

it t

ak

e th

e ti

le t

o h

it t

he

gro

un

d?

ab

ou

t 1.1

s

27.P

HY

SIC

SL

up

e to

sses

a b

all

up

to

Qu

yen

,w

ait

ing a

t a t

hir

d-s

tory

win

dow

,w

ith

an

init

ial

vel

ocit

y o

f 30 f

eet

per

sec

ond

.S

he

rele

ase

s th

e ball

fro

m a

hei

gh

t of

6 f

eet.

Th

eeq

uati

on h

52

16t2

130t

16 r

epre

sen

ts t

he

hei

gh

t h

of t

he

ball

aft

er t

seco

nd

s.If

th

eball

mu

st r

each

a h

eigh

t of

25 f

eet

for

Qu

yen

to

catc

h i

t,d

oes

the

ball

rea

ch Q

uyen

?E

xp

lain

.(H

int:

Su

bst

itu

te 2

5 f

or h

an

d u

se t

he

dis

crim

inan

t.)

No

;th

e d

iscri

min

an

t,2

316,is

neg

ati

ve

,so

th

ere

is n

o s

olu

tio

n.

1 } 43 } 4

1 } 23 } 4

3 } 21 } 2

1 } 4

1 } 31 } 2

1 } 2

Pra

cti

ce (

Avera

ge)

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y U

sin

g t

he Q

uad

rati

c F

orm

ula

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

Answers (Lesson 10-4)

Page 12: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A13 Glencoe Algebra 1

An

swers

Readin

g t

o L

earn

Math

em

ati

cs

So

lvin

g Q

uad

rati

c E

qu

ati

on

s b

y U

sin

g t

he Q

uad

rati

c F

orm

ula

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

©G

lencoe/M

cG

raw

-Hill

601

Gle

ncoe A

lgebra

1

Lesson 10-4

Pre

-Act

ivit

yH

ow

ca

n t

he Q

ua

dra

tic F

orm

ula

be u

sed

to

so

lve p

ro

ble

ms

inv

olv

ing

po

pu

lati

on

tren

ds?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-4

at

the

top

of

page

546 i

n y

our

textb

ook

.

You

r te

ach

er a

sks

you

to

pre

dic

t w

hen

17%

of

the

pop

ula

tion

wil

l co

nsi

st o

fp

eop

le b

orn

ou

tsid

e th

e U

nit

ed S

tate

s.W

hat

equ

ati

on s

hou

ld y

ou u

se t

om

ak

e th

e p

red

icti

on?

17 5

0.0

06

t22

0.0

80

t1

5.2

81

Read

ing

th

e L

ess

on

1.

Su

pp

ose

you

wan

t to

sol

ve

12

x2

17x

515 u

sin

g t

he

Qu

ad

rati

c F

orm

ula

.

a.

Wh

at

shou

ld y

ou d

o fi

rst?

Rew

rite

th

e e

qu

ati

on

in

th

e f

orm

ax

21

bx

1c

50.

b.

Wh

at

are

th

e valu

es y

ou n

eed

to

subst

itu

te f

or a

,b

,an

d c

in t

he

Qu

ad

rati

c F

orm

ula

?

a5

12,b

57,an

d c

52

15

c.

Ap

ply

th

e Q

uad

rati

c F

orm

ula

usi

ng t

he

abov

e valu

es,bu

t d

o n

ot s

olve

the

equ

ati

on.

x5

2.a

.Y

ou c

an

use

th

e d

iscr

imin

an

t to

det

erm

ine

the

nu

mber

of

real

root

s fo

r a q

uad

rati

ceq

uati

on.W

hat

is t

he

dis

crim

inan

t?

Th

e d

iscri

min

an

t is

th

e e

xp

ressio

n u

nd

er

the r

ad

ical

sig

n i

n t

he

Qu

ad

rati

c F

orm

ula

,b

22

4a

c.

b.

Com

ple

te t

he

state

men

ts b

elow

so

that

each

sta

tem

ent

is t

rue.

Wh

en t

he

valu

e of

th

e d

iscr

imin

an

t is

,th

ere

is o

ne

real

root

.

Wh

en t

he

valu

e of

th

e d

iscr

imin

an

t is

,th

ere

are

tw

o re

al

root

s.

Wh

en t

he

valu

e of

th

e d

iscr

imin

an

t is

,th

ere

are

no

real

root

s.

Help

ing

Yo

u R

em

em

ber

3.

To

hel

p r

emem

ber

th

e m

eth

ods

for

solv

ing a

qu

ad

rati

c eq

uati

on,ex

pla

in h

ow y

ou w

ould

choo

se t

he

bes

t m

eth

od f

or s

olvin

g a

qu

ad

rati

c eq

uati

on a

x2

1bx

1c

50.

Sam

ple

an

sw

er:

Use g

rap

hin

g f

or

ap

pro

xim

ate

so

luti

on

s.U

se t

he

Qu

ad

rati

c F

orm

ula

fo

r exact

so

luti

on

s.U

se f

acto

rin

g w

hen

th

e f

acto

rsare

easy t

o d

ete

rmin

e.U

se c

om

ple

tin

g t

he s

qu

are

wh

en

bis

an

even

nu

mb

er.

neg

ati

ve

po

sit

ive

ze

ro

27 6

Ï7

22

4w

(12)(

2w

15)

w}

}}

2(1

2)

©G

lencoe/M

cG

raw

-Hill

602

Gle

ncoe A

lgebra

1

Mech

an

ical

Co

nstr

ucti

on

s o

f P

ara

bo

las

A g

iven

lin

e an

d a

poi

nt

det

erm

ine

a p

ara

bol

a.

Her

e is

on

e w

ay t

o co

nst

ruct

th

e cu

rve.

Use

a r

igh

t tr

ian

gle

AB

C(o

r a s

tiff

pie

ce o

f re

ctan

gu

lar

card

boa

rd).

Pla

ce o

ne

leg o

f th

e tr

ian

gle

on

th

e giv

en l

ine

d.

Fast

en o

ne

end

of

a s

trin

g w

ith

len

gth

BC

at

the

giv

en p

oin

t F

an

d t

he

oth

er e

nd

to

the

tria

ngle

at

poi

nt

B.

Pu

t th

e ti

p o

f a p

enci

l at

poi

nt

Pan

d k

eep

th

e st

rin

g t

igh

t.

As

you

mov

e th

e tr

ian

gle

alo

ng t

he

lin

e d

,th

e p

oin

t of

you

r p

enci

l w

ill

trace

a p

ara

bol

a.

Dra

w t

he p

ara

bo

la d

ete

rm

ined

by

lin

e d

an

d p

oin

t F

.

1.

2.

3.

4.

5.

Use

you

r d

raw

ings

to c

omp

lete

th

is c

oncl

usi

on.T

he

gre

ate

r th

e d

ista

nce

of

poi

nt

Ffr

om

lin

e d

,th

e w

ider

the o

pen

ing

of

the p

ara

bo

la.

d

F

d

F

d

F

d

F

FPC

A

B

d

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-4

10-4

Answers (Lesson 10-4)

Page 13: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A14 Glencoe Algebra 1

Stu

dy G

uid

e a

nd I

nte

rven

tion

Exp

on

en

tial

Fu

ncti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

©G

lencoe/M

cG

raw

-Hill

603

Gle

ncoe A

lgebra

1

Lesson 10-5

Gra

ph

Exp

on

en

tial

Fu

nct

ion

s

Exp

on

en

tial

Fu

ncti

on

a f

unction d

efined b

y a

n e

quation o

f th

e f

orm

y5

ax,

where

a.

0 a

nd a

Þ1

You

can

use

valu

es o

f x

to f

ind

ord

ered

pair

s th

at

sati

sfy a

n e

xp

onen

tial

fun

ctio

n.T

hen

you

can

use

th

e or

der

ed p

air

s to

gra

ph

th

e fu

nct

ion

.

Gra

ph

y5

3x.

Sta

te

the y

-in

tercep

t.

Th

e y-i

nte

rcep

t is

1.

x

y

O

xy

22

}1 9}

21

}1 3}

01

13

29

Gra

ph

y5

12x

.U

se t

he

gra

ph

to

dete

rm

ine t

he a

pp

ro

xim

ate

va

lue o

f 1

220

.5.

Th

e valu

e of

122

0.5

is a

bou

t 2.

1 } 4

x

y

O2

8

xy

22

16

21

4

01

1}1 4}

2} 11 6}

1 } 4

1 } 4

Example

1Example

1Example

2Example

2

Exercises

Exercises

1.

Gra

ph

y5

0.3

x.S

tate

th

e y-i

nte

rcep

t.T

hen

use

th

e gra

ph

to

det

erm

ine

the

ap

pro

xim

ate

valu

e of

0.3

21.5

.U

se a

calc

ula

tor

to

con

firm

th

e valu

e.1;

ab

ou

t 6

Gra

ph

ea

ch

fu

ncti

on

.S

tate

th

e y

-in

tercep

t.

2.

y5

3x

11

23.

y5

12x

11

24.

y5

12x

22

21 x

y

O

x

y

O1

2

x

y

O1

2

1 } 21 } 3

x

y

O1

2

©G

lencoe/M

cG

raw

-Hill

604

Gle

ncoe A

lgebra

1

Iden

tify

Exp

on

en

tial

Beh

avio

rIt

is

som

etim

es u

sefu

l to

kn

ow i

f a s

et o

f d

ata

is

exp

onen

tial.

On

e w

ay t

o te

ll i

s to

obse

rve

the

shap

e of

th

e gra

ph

.A

not

her

way i

s to

obse

rve

the

patt

ern

in

th

e se

t of

data

.

Dete

rm

ine w

heth

er t

he s

et

of

da

ta d

isp

lay

s ex

po

nen

tia

l b

eh

av

ior.

x0

24

68

10

y64

32

16

84

2

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

Exp

on

en

tial

Fu

ncti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

Example

Example

Meth

od

1:G

rap

h t

he

Data

Th

e gra

ph

sh

ows

rap

idly

dec

reasi

ng

valu

es o

f y

as

xin

crea

ses.

Th

is i

sch

ara

cter

isti

c of

exp

onen

tial

beh

avio

r.

x

y

O2

8

Meth

od

2:L

ook

for

a P

att

ern

Th

e d

omain

valu

es i

ncr

ease

by r

egu

lar

inte

rvals

of

2,w

hil

e th

e ra

nge

valu

es h

ave

a

com

mon

fact

or o

f .S

ince

th

e d

omain

valu

es i

ncr

ease

by r

egu

lar

inte

rvals

an

d t

he

ran

ge

valu

es h

ave

a c

omm

on f

act

or,th

ed

ata

are

pro

bably

exp

onen

tial.

1 } 2

Exercises

Exercises

Dete

rm

ine w

heth

er t

he d

ata

in

ea

ch

ta

ble

dis

pla

y e

xp

on

en

tia

l b

eh

av

ior.

Ex

pla

inw

hy

or w

hy

no

t.

1.

2.

No

;th

e d

om

ain

valu

es a

re a

t re

gu

lar

Y

es;

the d

om

ain

valu

es a

re a

tin

terv

als

,an

d t

he r

an

ge v

alu

es h

ave

reg

ula

r in

terv

als

,an

d t

he r

an

ge

a c

om

mo

n d

iffe

ren

ce 5

.valu

es h

ave a

co

mm

on

facto

r 3.

3.

4.

Yes;

the d

om

ain

valu

es a

re a

t N

o;

the d

om

ain

valu

es a

re a

tre

gu

lar

inte

rvals

,an

d t

he r

an

ge

reg

ula

r in

terv

als

,b

ut

the r

an

ge

valu

es h

ave a

co

mm

on

facto

r .

valu

es d

o n

ot

ch

an

ge

.

5.

6.

Yes;

the d

om

ain

valu

es a

re a

t Y

es;

the d

om

ain

valu

es a

re a

tre

gu

lar

inte

rvals

,an

d t

he r

an

ge

reg

ula

r in

terv

als

,an

d t

he r

an

ge

valu

es h

ave a

co

mm

on

facto

r 0.5

.valu

es h

ave a

co

mm

on

facto

r .

1 } 3

x0

12

34

y}1 3}

}1 9}} 21 7}

} 81 1}} 2

1 43}

x2

50

510

y1

0.5

0.2

50.1

25

1 } 2

x2

10

12

3

y3

33

33

x2

11

35

y32

16

84

x0

12

3

y3

927

81

x0

12

3

y5

10

15

20

Answers (Lesson 10-5)

Page 14: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A15 Glencoe Algebra 1

An

swers

Skil

ls P

racti

ce

Exp

on

en

tial

Fu

ncti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

©G

lencoe/M

cG

raw

-Hill

605

Gle

ncoe A

lgebra

1

Lesson 10-5

Gra

ph

ea

ch

fu

ncti

on

.S

tate

th

e y

-in

tercep

t.T

hen

use

th

e g

ra

ph

to

dete

rm

ine t

he

ap

pro

xim

ate

va

lue o

f th

e g

iven

ex

press

ion

.U

se a

ca

lcu

lato

r t

o c

on

firm

th

e v

alu

e.

1.

y5

2x;2

2.3

2.

y5

12x

;1

221.6

1;

4.9

1;

5.8

Gra

ph

ea

ch

fu

ncti

on

.S

tate

th

e y

-in

tercep

t.

3.

y5

3(2

x)

4.

y5

3x

12

33

Dete

rm

ine w

heth

er t

he d

ata

in

ea

ch

ta

ble

dis

pla

y e

xp

on

en

tia

l b

eh

av

ior.

Ex

pla

inw

hy

or w

hy

no

t.

5.

6.

No

;th

e d

om

ain

valu

es a

re a

t Y

es;

the d

om

ain

valu

es a

re a

t re

gu

lar

inte

rvals

an

d t

he r

an

ge

reg

ula

r in

terv

als

an

d t

he r

an

ge

valu

es h

ave a

co

mm

on

valu

es h

ave a

co

mm

on

facto

r 0.5

.d

iffe

ren

ce 3

.

7.

8.

Yes;

the d

om

ain

valu

es a

re a

t N

o;

the d

om

ain

valu

es a

re a

t re

gu

lar

inte

rvals

an

d t

he r

an

ge

reg

ula

r in

terv

als

an

d t

he r

an

ge

valu

es h

ave a

co

mm

on

facto

r 2.

valu

es h

ave a

co

mm

on

d

iffe

ren

ce 2

0.

x50

30

10

210

y90

70

50

30

x4

812

16

y20

40

80

160

x0

510

15

y20

10

52.5

x2

32

22

10

y9

12

15

18

x

y

Ox

y

O

x

y

Ox

y

O

1 } 31 } 3

©G

lencoe/M

cG

raw

-Hill

606

Gle

ncoe A

lgebra

1

Gra

ph

ea

ch

fu

ncti

on

.S

tate

th

e y

-in

tercep

t.T

hen

use

th

e g

ra

ph

to

dete

rm

ine t

he

ap

pro

xim

ate

va

lue o

f th

e g

iven

ex

press

ion

.U

se a

ca

lcu

lato

r t

o c

on

firm

th

e v

alu

e.

1.

y5

12x

;1

220.5

1;

3.2

2.

y5

3x;3

1.9

1;

8.1

3.

y5

12x

;1

221.4

1;

7.0

Gra

ph

ea

ch

fu

ncti

on

.S

tate

th

e y

-in

tercep

t.

4.

y5

4(2

x)

11

55.

y5

2(2

x2

1)

06.

y5

0.5

(3x

23)

21

Dete

rm

ine w

heth

er t

he d

ata

in

ea

ch

ta

ble

dis

pla

y e

xp

on

en

tia

l b

eh

av

ior.

Ex

pla

inw

hy

or w

hy

no

t.

7.

8.

Yes;

the d

om

ain

valu

es a

re a

t N

o;

the d

om

ain

valu

es a

re a

t re

gu

lar

inte

rvals

an

d t

he r

an

ge

reg

ula

r in

terv

als

an

d t

he r

an

ge

valu

es h

ave a

co

mm

on

valu

es h

ave a

co

mm

on

fa

cto

r 0.2

5.

dif

fere

nce 7

.

9.LE

AR

NIN

GM

s.K

lem

per

er t

old

her

En

gli

sh c

lass

th

at

each

wee

k s

tud

ents

ten

d t

o fo

rget

one

sixth

of

the

voc

abu

lary

wor

ds

they

lea

rned

th

e p

revio

us

wee

k.S

up

pos

e a s

tud

ent

learn

s 60 w

ord

s.T

he

nu

mber

of

wor

ds

rem

ember

ed c

an

be

des

crib

ed b

y t

he

fun

ctio

n

W(x

) 5

601

2x,w

her

e x

is t

he

nu

mber

of

wee

ks

that

pass

.H

ow m

an

y w

ord

s w

ill

the

stu

den

t re

mem

ber

aft

er 3

wee

ks?

ab

ou

t 35

10.B

IOLO

GY

Su

pp

ose

a c

erta

in c

ell

rep

rod

uce

s it

self

in

fou

r h

ours

.If

a l

ab r

esea

rch

erbeg

ins

wit

h 5

0 c

ells

,h

ow m

an

y c

ells

wil

l th

ere

be

aft

er o

ne

day,

two

days,

an

d t

hre

ed

ays?

(H

int:

Use

th

e ex

pon

enti

al

fun

ctio

n y

550(2

x).

)3200 c

ells;

204,8

00 c

ells;

13,1

07,2

00 c

ells

5 } 6

x21

18

15

12

y30

23

16

9

x2

58

11

y480

120

30

7.5

x

y

Ox

y

O

x

y

O

x

y

Ox

y

Ox

y

O

1 } 41 } 4

1} 1

01

} 10

Pra

cti

ce (

Avera

ge)

Exp

on

en

tial

Fu

ncti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

Answers (Lesson 10-5)

Page 15: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A16 Glencoe Algebra 1

Readin

g t

o L

earn

Math

em

ati

cs

Exp

on

en

tial

Fu

ncti

on

s

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

©G

lencoe/M

cG

raw

-Hill

607

Gle

ncoe A

lgebra

1

Lesson 10-5

Pre

-Act

ivit

yH

ow

ca

n e

xp

on

en

tia

l fu

ncti

on

s b

e u

sed

in

art?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-5

at

the

top

of

page

554 i

n y

our

textb

ook

.

If M

r.W

art

her

had

carv

ed a

nin

th l

ayer

of

pli

ers,

how

man

y p

lier

s w

ould

he

have

carv

ed?

29

or

512 p

liers

Read

ing

th

e L

ess

on

1.

Th

e gra

ph

s of

tw

o ex

pon

enti

al

fun

ctio

ns

of t

he

form

y5

ax

are

sh

own

bel

ow.

A.

B.

a.

In G

rap

h A

,th

e valu

e of

ais

gre

ate

r th

an

an

d l

ess

than

.T

he

yvalu

es d

ecre

ase

as

the

xvalu

es

.

b.

In G

rap

h B

,th

e valu

e of

ais

gre

ate

r th

an

.T

he

yvalu

es

as

the

xvalu

es i

ncr

ease

.

2.a

.W

hen

you

loo

k f

or a

patt

ern

of

exp

onen

tial

beh

avio

r in

a s

et o

f d

ata

,w

hat

is t

he

patt

ern

you

are

loo

kin

g f

or?

Valu

es o

f x

(do

main

valu

es)

that

are

at

reg

ula

r in

terv

als

an

d v

alu

es o

fy

(ran

ge v

alu

es)

that

have a

co

mm

on

facto

r.

b.

If a

set

of

data

has

a n

egati

ve

com

mon

fact

or,d

oes

it d

isp

lay e

xp

onen

tial

beh

avio

r?

No

;th

e c

om

mo

n f

acto

r n

eed

s t

o b

e g

reate

r th

an

0 a

nd

no

t eq

ual

to 1

.

Help

ing

Yo

u R

em

em

ber

3.

Wh

at

com

pari

son

s ca

n y

ou m

ak

e bet

wee

n t

he

qu

ad

rati

c fu

nct

ion

y5

x2

an

d t

he

exp

onen

tial

fun

ctio

n y

52

xto

hel

p r

emem

ber

th

e d

iffe

ren

ces

bet

wee

n q

uad

rati

c an

dex

pon

enti

al

fun

ctio

ns?

Sam

ple

an

sw

er:

In t

he q

uad

rati

c f

un

cti

on

,th

e v

ari

ab

le i

s t

he b

ase a

nd

the e

xp

on

en

t is

a n

um

ber;

in t

he e

xp

on

en

tial

fun

cti

on

,th

e v

ari

ab

le i

s t

he

exp

on

en

t an

d t

he b

ase i

s a

nu

mb

er.

incre

ase

1

incre

ase

10

x

y

O

x

y

O

©G

lencoe/M

cG

raw

-Hill

608

Gle

ncoe A

lgebra

1

Wri

tin

g E

xp

ressio

ns o

f A

rea i

n F

acto

red

Fo

rm

Writ

e a

n e

xp

ress

ion

in

fa

cto

red

fo

rm

fo

r t

he a

rea

Ao

f th

e

sha

ded

reg

ion

in

ea

ch

fig

ure b

elo

w.

1.

2.

A5

2r

2(4

2p

)

A5

(x1

y)(

x2

y)

3.

4.

A5

(a1

b)(

a2

b)

A5

r2(8

1p

)

5.

6.

A5

p(R

12

r)(R

22

r)A

5a

(3a

12

b)

7.

8.

A5

x218

22

A5

r2(p

21)

p } 2

r

r

2x

4x

4x

90

8

b

2a

a

a

rr

r

R

rp } 8

4r

rr

b a

r

r

x x

xx

y y

yy

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-5

10-5

Answers (Lesson 10-5)

Page 16: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A17 Glencoe Algebra 1

An

swers

Stu

dy G

uid

e a

nd I

nte

rven

tion

Gro

wth

an

d D

ecay

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

©G

lencoe/M

cG

raw

-Hill

609

Gle

ncoe A

lgebra

1

Lesson 10-6

Exp

on

en

tial

Gro

wth

Pop

ula

tion

in

crea

ses

an

d g

row

th o

f m

onet

ary

in

ves

tmen

ts a

reex

am

ple

s of

ex

po

nen

tia

l g

ro

wth

.T

his

mea

ns

that

an

in

itia

l am

oun

t in

crea

ses

at

a s

tead

yra

te o

ver

tim

e.

The g

enera

l equation f

or

exponential gro

wth

is y

5C

(1 1

r)t .

•y

repre

sents

the f

inal am

ount.

Exp

on

en

tial

Gro

wth

•C

repre

sents

the initia

l am

ount.

•r

repre

sents

the r

ate

of

change e

xpre

ssed a

s a

decim

al.

•t

repre

sents

tim

e.

PO

PU

LATIO

NT

he

po

pu

lati

on

of

Jo

hn

son

Cit

y i

n 1

995 w

as

25,0

00.S

ince t

hen

,th

e p

op

ula

tio

n h

as

gro

wn

at

an

av

era

ge r

ate

of

3.2

% e

ach

yea

r.

a.

Writ

e a

n e

qu

ati

on

to

rep

rese

nt

the

po

pu

lati

on

of

Jo

hn

son

Cit

y s

ince 1

995.

Th

e ra

te 3

.2%

can

be

wri

tten

as

0.0

32.

y5

C(1

1r)

t

y5

25,0

00(1

10.0

32)t

y5

25,0

00(1

.032)t

b.

Acco

rd

ing

to

th

e e

qu

ati

on

,w

ha

t w

ill

the p

op

ula

tio

n o

f J

oh

nso

n C

ity

be i

nth

e y

ea

r 2

005?

In 2

005,t

wil

l eq

ual

2005 2

1995 o

r 10.

Su

bst

itu

te 1

0 f

or t

in t

he

equ

ati

on f

rom

p

art

a.

y5

25,0

00(1

.032)1

0t

51

0

<34,2

56

In 2

005,th

e p

opu

lati

on o

f Joh

nso

n C

ity w

ill

be

abou

t 34,2

56.

INV

ES

TM

EN

TT

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Ga

rcia

s h

av

e $

12,0

00 i

n a

sa

vin

gs

acco

un

t.T

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an

k p

ay

s 3.5

% i

nte

rest

on

sa

vin

gs

acco

un

ts,

co

mp

ou

nd

ed

mo

nth

ly.

Fin

d t

he b

ala

nce i

n 3

yea

rs.

Th

e ra

te 3

.5%

can

be

wri

tten

as

0.0

35.

Th

e sp

ecia

l eq

uati

on f

or c

omp

oun

d

inte

rest

is

A5

P11

12n

t ,w

her

e A

rep

rese

nts

th

e bala

nce

,P

is t

he

init

ial

am

oun

t,r

rep

rese

nts

th

e an

nu

al

rate

exp

ress

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s a d

ecim

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pre

sen

ts t

he

nu

mber

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tim

es t

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inte

rest

is

com

pou

nd

edea

ch y

ear,

an

d t

rep

rese

nts

th

e n

um

ber

of

yea

rs t

he

mon

ey i

s in

ves

ted

.

A5

P11

12n

t

A5

12,0

0011

123

6

A<

12,0

00(1

.00292)3

6

A<

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In t

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the

acc

oun

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ill

be

$13,3

28.0

9.

0.0

35

}1

2

r } n

r } n

Example

1Example

1Example

2Example

2

Exercises

Exercises

1.P

OP

ULA

TIO

NT

he

pop

ula

tion

of

the

Un

ited

2.IN

VE

ST

ME

NT

Det

erm

ine

the

Sta

tes

has

bee

n i

ncr

easi

ng a

t an

aver

age

am

oun

t of

an

in

ves

tmen

t of

$2500 i

f it

an

nu

al

rate

of

0.9

1%

.If

th

e p

opu

lati

on o

f th

eis

in

ves

ted

at

in i

nte

rest

rate

of

5.2

5%

U

nit

ed S

tate

s w

as

abou

t 284,9

05,4

00 i

n t

he

co

mp

oun

ded

mon

thly

for

4 y

ears

.yea

r 2001,p

red

ict

the

U.S

.p

opu

lati

on i

n t

he

$3082.7

8yea

r 2005.

Sourc

e:

U. S

. Cen

sus

Bure

auab

ou

t 295,4

18,3

75

3.P

OP

ULA

TIO

NIt

is

esti

mate

d t

hat

the

4.IN

VE

ST

ME

NT

Det

erm

ine

the

pop

ula

tion

of

the

wor

ld i

s in

crea

sin

g a

t an

am

oun

t of

an

in

ves

tmen

t of

$100,0

00

aver

age

an

nu

al

rate

of

1.3

%.If

th

e p

opu

lati

on

if i

t is

in

ves

ted

at

an

in

tere

st r

ate

of

of

th

e w

orld

was

abou

t 6,1

67,0

07,0

00 i

n t

he

5.2

% c

omp

oun

ded

qu

art

erly

for

yea

r 2001,p

red

ict

the

wor

ld p

opu

lati

on i

n t

he

12 y

ears

.$185,8

88.8

7yea

r 2010.

Sourc

e:

U. S

. Cen

sus

Bure

auab

ou

t 6,9

27,2

27,4

83

©G

lencoe/M

cG

raw

-Hill

610

Gle

ncoe A

lgebra

1

Exp

on

en

tial

Deca

yR

ad

ioact

ive

dec

ay a

nd

dep

reci

ati

on a

re e

xam

ple

s of

ex

po

nen

tia

ld

eca

y.T

his

mea

ns

that

an

in

itia

l am

oun

t d

ecre

ase

s at

a s

tead

y r

ate

over

a p

erio

d o

f ti

me.

The g

enera

l equation f

or

exponential decay is y

5C

(1 2

r)t.

•y

repre

sents

the f

inal am

ount.

Exp

on

en

tial

Decay

•C

repre

sents

the initia

l am

ount.

•r

repre

sents

the r

ate

of

decay e

xpre

ssed a

s a

decim

al.

•t

repre

sents

tim

e.

DE

PR

EC

IAT

ION

Th

e o

rig

ina

l p

ric

e o

f a

tra

cto

r w

as

$45,0

00.T

he

va

lue o

f th

e t

ra

cto

r d

ecrea

ses

at

a s

tea

dy

ra

te o

f 12%

per y

ea

r.

a.

Writ

e a

n e

qu

ati

on

to

rep

rese

nt

the v

alu

e o

f th

e t

ra

cto

r s

ince i

t w

as

pu

rch

ase

d.

Th

e ra

te 1

2%

can

be

wri

tten

as

0.1

2.

y5

C(1

2r)

tG

enera

l equation f

or

exponential decay

y5

45,0

00(1

20.1

2)t

C5

45,0

00 a

nd r

50.1

2

y5

45,0

00(0

.88)t

Sim

plif

y.

b.

Wh

at

is t

he v

alu

e o

f th

e t

ra

cto

r i

n 5

yea

rs?

y5

45,0

00(0

.88)t

Equation f

or

decay f

rom

part

a

y5

45,0

00(0

.88)5

t5

5

y<

23,7

47.9

4U

se a

calc

ula

tor.

In 5

yea

rs,th

e tr

act

or w

ill

be

wor

th a

bou

t $23,7

47.9

4.

1.P

OP

ULA

TIO

NT

he

pop

ula

tion

of

Bu

lgari

a h

as

bee

n d

ecre

asi

ng a

t an

an

nu

al

rate

of

1.3

%.If

th

e p

opu

lati

on o

f B

ulg

ari

a w

as

abou

t 7,7

97,0

00 i

n t

he

yea

r 2000,

pre

dic

t it

s p

opu

lati

on i

n t

he

yea

r 2010.

Sourc

e:

U. S

. Cen

sus

Bure

auab

ou

t 6,8

41,0

00

2.D

EP

RE

CIA

TIO

NC

arl

Gos

sell

is

a m

ach

inis

t.H

e bou

gh

t so

me

new

mach

iner

yfo

r abou

t $125,0

00.H

e w

an

ts t

o ca

lcu

late

th

e valu

e of

th

e m

ach

iner

y o

ver

th

en

ext

10 y

ears

for

tax p

urp

oses

.If

th

e m

ach

iner

y d

epre

ciate

s at

the

rate

of

15%

per

yea

r,w

hat

is t

he

valu

e of

th

e m

ach

iner

y (

to t

he

nea

rest

$100)

at

the

end

of

10 y

ears

?ab

ou

t $24,6

00

3.A

RC

HA

EO

LO

GY

Th

e h

alf

-lif

eof

a r

ad

ioact

ive

elem

ent

is d

efin

ed a

s th

e ti

me

that

it t

ak

es f

or o

ne-

half

a q

uan

tity

of

the

elem

ent

to d

ecay.

Rad

ioact

ive

Carb

on-1

4 i

s fo

un

d i

n a

ll l

ivin

g o

rgan

ism

s an

d h

as

a h

alf

-lif

e of

5730 y

ears

.C

onsi

der

a l

ivin

g o

rgan

ism

wit

h a

n o

rigin

al

con

cen

trati

on o

f C

arb

on-1

4 o

f 100 g

ram

s.

a.

If t

he

organ

ism

liv

ed 5

730 y

ears

ago,

wh

at

is t

he

con

cen

trati

on o

f C

arb

on-1

4 t

oday?

50 g

b.

If t

he

organ

ism

liv

ed 1

1,4

60 y

ears

ago,

det

erm

ine

the

con

cen

trati

on o

f C

arb

on-1

4 t

oday.

25 g

4.D

EP

RE

CIA

TIO

NA

new

car

cost

s $32,0

00.It

is

exp

ecte

d t

o d

epre

ciate

12%

each

yea

r fo

r 4 y

ears

an

d t

hen

dep

reci

ate

8%

each

yea

r th

erea

fter

.F

ind

th

e valu

e of

the

car

in 6

yea

rs.

ab

ou

t $16,2

42.6

3

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

Gro

wth

an

d D

ecay

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

Example

Example

Exercises

Exercises

Answers (Lesson 10-6)

Page 17: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A18 Glencoe Algebra 1

Skil

ls P

racti

ce

Gro

wth

an

d D

ecay

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

©G

lencoe/M

cG

raw

-Hill

611

Gle

ncoe A

lgebra

1

Lesson 10-6

PO

PU

LA

TIO

NF

or E

xercis

es

1 a

nd

2,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Th

e p

opu

lati

on o

f N

ew Y

ork

Cit

y i

ncr

ease

d f

rom

7,3

22,5

64 i

n 1

990 t

o 8,0

08,2

78 i

n 2

000.T

he

an

nu

al

rate

of

pop

ula

tion

in

crea

se f

or t

he

per

iod

was

abou

t 0.9

%.

Sourc

e:

ww

w.n

yc.g

ov

1.

Wri

te a

n e

qu

ati

on f

or t

he

pop

ula

tion

tyea

rs a

fter

1990.

P5

7,3

22,5

64

(1.0

09)t

2.

Use

th

e eq

uati

on t

o p

red

ict

the

pop

ula

tion

of

New

Yor

k C

ity i

n 2

010.

ab

ou

t 8,7

60,0

00

SA

VIN

GS

Fo

r E

xercis

es

3 a

nd

4,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Th

e F

resh

an

d G

reen

Com

pan

y h

as

a s

avin

gs

pla

n f

or i

ts e

mp

loyee

s.If

an

em

plo

yee

mak

esan

in

itia

l co

ntr

ibu

tion

of

$1000,th

e co

mp

an

y p

ays

8%

in

tere

st c

omp

oun

ded

qu

art

erly

.

3.

If a

n e

mp

loyee

part

icip

ati

ng i

n t

he

pla

n w

ith

dra

ws

the

bala

nce

of

the

acc

oun

t aft

er

5 y

ears

,h

ow m

uch

wil

l be

in t

he

acc

oun

t?$1485.9

5

4.

If a

n e

mp

loyee

part

icip

ati

ng i

n t

he

pla

n w

ith

dra

ws

the

bala

nce

of

the

acc

oun

t aft

er

35 y

ears

,h

ow m

uch

wil

l be

in t

he

acc

oun

t?$15,9

96.4

7

5.H

OU

SIN

GM

r.an

d M

rs.B

oyce

bou

gh

t a h

ouse

for

$96,0

00 i

n 1

995.T

he

real

esta

tebro

ker

in

dic

ate

d t

hat

hou

ses

in t

hei

r are

a a

re a

pp

reci

ati

ng a

t an

aver

age

an

nu

al

rate

of

4%

.If

th

e ap

pre

ciati

on r

emain

s st

ead

y a

t th

is r

ate

,w

hat

wil

l be

the

valu

e of

th

e B

oyce

’sh

ome

in 2

005?

ab

ou

t $142,1

03

MA

NU

FAC

TU

RIN

GF

or E

xercis

es

6 a

nd

7,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Zel

ler

Ind

ust

ries

bou

gh

t a p

iece

of

wea

vin

g e

qu

ipm

ent

for

$60,0

00.It

is

exp

ecte

d t

od

epre

ciate

at

an

aver

age

rate

of

10%

per

yea

r.

6.

Wri

te a

n e

qu

ati

on f

or t

he

valu

e of

th

e p

iece

of

equ

ipm

ent

aft

er t

yea

rs.

E5

60,0

00(0

.90)t

7.

Fin

d t

he

valu

e of

th

e p

iece

of

equ

ipm

ent

aft

er 6

yea

rs.

ab

ou

t $31,8

86

8.FIN

AN

CE

SK

yle

saved

$500 f

rom

a s

um

mer

job

.H

e p

lan

s to

sp

end

10%

of

his

savin

gs

each

wee

k o

n v

ari

ous

form

s of

en

tert

ain

men

t.A

t th

is r

ate

,h

ow m

uch

wil

l K

yle

have

left

aft

er 1

5 w

eek

s?$102.9

5

9.T

RA

NS

PO

RTA

TIO

NT

iffa

ny’s

mot

her

bou

gh

t a c

ar

for

$9000 f

ive

yea

rs a

go.

Sh

e w

an

tsto

sel

l it

to

Tif

fan

y b

ase

d o

n a

15%

an

nu

al

rate

of

dep

reci

ati

on.A

t th

is r

ate

,h

ow m

uch

wil

l T

iffa

ny p

ay f

or t

he

car?

ab

ou

t $3993

©G

lencoe/M

cG

raw

-Hill

612

Gle

ncoe A

lgebra

1

CO

MM

UN

ICA

TIO

NS

Fo

r E

xercis

es

1 a

nd

2,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Com

mer

cial

non

-mu

sic

rad

io s

tati

ons

incr

ease

d a

t an

aver

age

an

nu

al

rate

of

3.1

% f

rom

1996 t

o 2000.C

omm

erci

al

rad

io s

tati

ons

in t

his

for

mat

nu

mber

ed 1

262 i

n 1

996.

Sourc

e:

M S

treet

Cor

pora

tion,

Nas

hvill

e, T

N

1.

Wri

te a

n e

qu

ati

on f

or t

he

nu

mber

of

rad

io s

tati

ons

for

tyea

rs a

fter

1996.

R5

1262(1

.031)t

2.

If t

he

tren

d c

onti

nu

es,p

red

ict

the

nu

mber

of

rad

io s

tati

ons

in t

his

for

mat

for

the

yea

r 2006.

ab

ou

t 1713 s

tati

on

s

3.IN

VE

ST

ME

NT

SD

eter

min

e th

e am

oun

t of

an

in

ves

tmen

t if

$500 i

s in

ves

ted

at

an

inte

rest

rate

of

4.2

5%

com

pou

nd

ed q

uart

erly

for

12 y

ears

.$830.4

1

4.IN

VE

ST

ME

NT

SD

eter

min

e th

e am

oun

t of

an

in

ves

tmen

t if

$300 i

s in

ves

ted

at

an

inte

rest

rate

of

6.7

5%

com

pou

nd

ed s

emia

nn

uall

y f

or 2

0 y

ears

.$1131.7

3

5.H

OU

SIN

GT

he

Gre

ens

bou

gh

t a c

ond

omin

ium

for

$110,0

00 i

n 2

000.If

its

valu

eap

pre

ciate

s at

an

aver

age

rate

of

6%

per

yea

r,w

hat

wil

l th

e valu

e be

in 2

005?

ab

ou

t$147,2

05

DE

FO

RE

STA

TIO

NF

or E

xercis

es

6 a

nd

7,

use

th

e f

oll

ow

ing

in

form

ati

on

.

Du

rin

g t

he

1990s,

the

fore

sted

are

a o

f G

uate

mala

dec

rease

d a

t an

aver

age

rate

of

1.7

%.

Sourc

e:

ww

w.w

orld

bank

.org

6.

If t

he

fore

sted

are

a i

n G

uate

mala

in

1990 w

as

abou

t 34,4

00 s

qu

are

kil

omet

ers,

wri

te a

neq

uati

on f

or t

he

fore

sted

are

a f

or t

yea

rs a

fter

1990.

C5

34,4

00(0

.983)t

7.

If t

his

tre

nd

con

tin

ues

,p

red

ict

the

fore

sted

are

a i

n 2

015.

ab

ou

t 22,4

00 k

m2

8.B

US

INE

SS

A p

iece

of

mach

iner

y v

alu

ed a

t $25,0

00 d

epre

ciate

s at

a s

tead

y r

ate

of

10%

yea

rly.

Wh

at

wil

l th

e valu

e of

th

e p

iece

of

mach

iner

y b

e aft

er 7

yea

rs?

ab

ou

t $11,9

57

9.T

RA

NS

PO

RTA

TIO

NA

new

car

cost

s $18,0

00.It

is

exp

ecte

d t

o d

epre

ciate

at

an

aver

age

rate

of

12%

per

yea

r.F

ind

th

e valu

e of

th

e ca

r in

8 y

ears

.ab

ou

t $6473

10.P

OP

ULA

TIO

NT

he

pop

ula

tion

of

Osa

ka,Jap

an

dec

lin

ed a

t an

aver

age

an

nu

al

rate

of

0.0

5%

for

th

e fi

ve

yea

rs b

etw

een

1995 a

nd

2000.If

th

e p

opu

lati

on o

f O

sak

a w

as

11,0

13,0

00 i

n 2

000 a

nd

it

con

tin

ues

to

dec

lin

e at

the

sam

e ra

te,p

red

ict

the

pop

ula

tion

in

2050.

ab

ou

t 10,7

41,0

00

Pra

cti

ce (

Avera

ge)

Gro

wth

an

d D

ecay

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

Answers (Lesson 10-6)

Page 18: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A19 Glencoe Algebra 1

An

swers

Readin

g t

o L

earn

Math

em

ati

cs

Gro

wth

an

d D

ecay

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

©G

lencoe/M

cG

raw

-Hill

613

Gle

ncoe A

lgebra

1

Lesson 10-6

Pre

-Act

ivit

yH

ow

ca

n e

xp

on

en

tia

l g

ro

wth

be u

sed

to

pred

ict

futu

re s

ale

s?

Rea

d t

he

intr

odu

ctio

n t

o L

esso

n 1

0-6

at

the

top

of

page

561 i

n y

our

textb

ook

.

Su

pp

ose

you

wan

t to

pre

dic

t th

e am

oun

t of

mon

ey a

n a

ver

age

hou

seh

old

wil

l sp

end

on

res

tau

ran

t m

eals

in

th

e yea

r 2005.W

hat

nu

mber

sh

ould

be

subst

itu

ted

for

t?

11

Read

ing

th

e L

ess

on

Ma

tch

an

eq

ua

tio

n t

o e

ach

sit

ua

tio

n,

an

d t

hen

in

dic

ate

wh

eth

er t

he s

itu

ati

on

is

an

ex

am

ple

of

ex

po

nen

tia

l g

ro

wth

or d

eca

y.

1.

A c

oin

had

a v

alu

e of

$1.1

7 i

n 1

995.It

s valu

e h

as

bee

n i

ncr

easi

ng a

t a r

ate

of

9%

p

er y

ear.

A;

gro

wth

A.

y5

1.1

7(1

.09)t

B.

y5

1.1

7(0

.91)t

2.

A b

usi

nes

s ow

ner

has

just

paid

$6000 f

or a

com

pu

ter.

It d

epre

ciate

s at

a r

ate

of

22%

p

er y

ear.

How

mu

ch w

ill

it b

e w

orth

in

5 y

ears

?B

;d

ecay

A.

A5

6000(1

.22)5

B.

A5

6000(0

.78)5

3.

A c

ity h

ad

a p

opu

lati

on o

f 14,3

58 r

esid

ents

in

1999.S

ince

th

en,it

s p

opu

lati

on h

as

bee

nd

ecre

asi

ng a

t a r

ate

of

abou

t 5.5

% p

er y

ear.

B;

decay

A.

A5

14,3

58(1

.055)t

B.

A5

14,3

58(0

.945)t

4.

Gin

a d

epos

ited

$1500 i

n a

n a

ccou

nt

that

pays

4%

in

tere

st c

omp

oun

ded

qu

art

erly

.W

hat

wil

l be

the

wor

th o

f th

e acc

oun

t in

2 y

ears

if

she

mak

es n

o d

epos

its

an

d n

ow

ith

dra

wals

?B

;g

row

th

A.

A5

1500(1

.02)2

B.

A5

1500(1

.02)8

Help

ing

Yo

u R

em

em

ber

5.

How

can

you

use

wh

at

you

kn

ow a

bou

t ra

isin

g a

nu

mber

to

the

0 p

ower

to

hel

p y

oure

mem

ber

wh

at

Cre

pre

sen

ts i

n t

he

exp

onen

tial

gro

wth

equ

ati

on A

5C

(1 1

r)t

an

d t

he

exp

onen

tial

dec

ay e

qu

ati

on A

5C

(1 2

r)t ?

Sam

ple

an

sw

er:

Th

e i

nit

ial

am

ou

nt

is t

he a

mo

un

t b

efo

re a

ny t

ime h

as

passed

,th

at

is,w

hen

t5

0.W

hen

t5

0,C

(1 1

r)t

5C

(1 1

r)0

5C

(1)

5C

an

d C

(1 2

r)t

5C

(1 2

r)0

5C

(1)

5C

.S

o C

rep

resen

ts t

he i

nit

ial

am

ou

nt.

©G

lencoe/M

cG

raw

-Hill

614

Gle

ncoe A

lgebra

1

Cu

rio

us C

ircle

sT

wo

circ

les

can

be

arr

an

ged

in

fou

r w

ays:

one

circ

le c

an

be

insi

de

the

oth

er,th

ey c

an

be

sep

ara

te,th

ey c

an

over

lap

,or

th

ey c

an

coi

nci

de.

In h

ow m

an

y w

ays

can

a g

iven

nu

mber

of

circ

les

be

eith

er s

epara

te o

rin

sid

e ea

ch o

ther

? (T

he

situ

ati

ons

in w

hic

h t

he

circ

les

over

lap

or

coin

cid

e are

not

cou

nte

d h

ere.

)

For

3 c

ircl

es,th

ere

are

4 d

iffe

ren

t p

ossi

bil

itie

s.

So

lve e

ach

pro

ble

m.

Ma

ke d

ra

win

gs

to s

ho

w y

ou

r a

nsw

ers.

1.

Sh

ow t

he

dif

fere

nt

ways

in w

hic

h 2

cir

cles

can

be

sep

ara

te o

rin

sid

e ea

ch o

ther

.H

ow m

an

y w

ays

are

th

ere?

two

ways

2.

Sh

ow t

he

dif

fere

nt

ways

for

4 c

ircl

es.H

ow m

an

y w

ays

are

th

ere?

nin

e w

ays

3.

Use

you

r an

swer

for

Exer

cise

2 t

o sh

ow t

hat

the

nu

mber

of

ways

for

5 c

ircl

es i

s at

least

18.

Fir

st,

dra

w a

n e

xtr

a c

ircle

next

toeach

of

the w

ays f

or

4 c

ircle

s.T

hen

dra

w a

cir

cle

aro

un

d e

ach

of

the w

ays f

or

4 c

ircle

s.

4.

Fin

d t

he

nu

mber

of

ways

for

5 c

ircl

es.S

how

you

r d

raw

ings

on a

sep

ara

te s

hee

t of

pap

er.

20 w

ays

1 5 8

23

4

67

9

21

23

41

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-6

10-6

Answers (Lesson 10-6)

Page 19: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A20 Glencoe Algebra 1

Stu

dy G

uid

e a

nd I

nte

rven

tion

Geo

metr

ic S

eq

uen

ces

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-7

10-7

©G

lencoe/M

cG

raw

-Hill

615

Gle

ncoe A

lgebra

1

Lesson 10-7

Geo

metr

ic S

eq

uen

ces

A g

eo

metr

ic s

eq

uen

ce

is a

sequ

en

ce i

n w

hic

h e

ach

term

aft

er

the n

on

zero

fir

st t

erm

is

fou

nd

by m

ult

iply

ing t

he p

revio

us

term

by a

con

stan

t ca

lled

th

eco

mm

on

ra

tio

.

Geo

metr

ic

a s

equence o

f num

bers

of

the f

orm

a,

ar,

ar

2,

ar

3,

…,

Exam

ple

:1,

2,

4,

8,

16,

Seq

uen

ce

where

0,

and r

Þ0 o

r 1

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s g

eo

metr

ic.

Exercises

Exercises

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s g

eo

metr

ic.

1.

2,4,6,8,10,…

2.

2,4,8,16,32,…

3.

210,

25,

22.5

,2

1.2

5,…

no

yes

yes

4.

100,400,1600,6400,…

5.

,,

,,…

6.

,,

,,…

yes

no

yes

Fin

d t

he n

ex

t th

ree t

erm

s i

n e

ach

geo

metr

ic s

eq

uen

ce.

7.

100,300,900,2700,…

8.

,,

,,…

9.

80,40,20,10,…

8100,24,3

00,72,9

00

,,

5,

,

Fin

d t

he n

th t

erm

of

ea

ch

geo

metr

ic s

eq

uen

ce.

10.a

15

5,n

56,r

53

11.

a1

53,n

55,r

54

12.

a1

52

5,n

57,r

52

2

1215

768

2320

5 } 4

5 } 2

1} 1

28

1} 6

4

1} 3

2

1} 1

6

1 } 8

1 } 4

1 } 2

1} 8

1

1} 2

7

1 } 9

1 } 3

1 } 5

1 } 4

1 } 3

1 } 2

Example

1Example

1

Example

2Example

2

a.

3,

6,

9,

12,

15,

In t

his

sequ

en

ce,each

term

is

fou

nd

by

ad

din

g 3

to t

he p

revio

us

term

.T

he

sequ

en

ce i

s ari

thm

eti

c an

d n

ot

geom

etr

ic.

b.

1,

4,

16,

64,

In t

his

sequ

en

ce,each

term

is

fou

nd

by

mu

ltip

lyin

g t

he p

revio

us

term

by 4

.T

he

sequ

en

ce i

s geom

etr

ic.

a.

8,

24,

2,

21,

Th

e c

om

mon

fact

or

is

or

2.U

se t

his

info

rmati

on

to f

ind

th

e n

ext

thre

e t

erm

s.

(21) 12

25

1225

2

12212

25T

he n

ext

thre

e t

erm

s are

,

2,an

d

.1 } 8

1 } 4

1 } 2

1 } 8

1 } 2

1 } 4

1 } 4

1 } 2

1 } 2

1 } 2

1 } 2

1 } 2

24

}8

b.

7,

14,

28,

56,

Th

e c

om

mon

rati

o i

s or

2.U

se t

his

info

rmati

on

to f

ind

th

e n

ext

thre

e t

erm

s.

56(2

) 5

112

112(2

) 5

224

224(2

) 5

448

Th

e n

ext

thre

e t

erm

s are

112,224,448.

14

}7

Fin

d t

he n

ex

t th

ree t

erm

s i

n e

ach

geo

metr

ic s

eq

uen

ce.

©G

lencoe/M

cG

raw

-Hill

616

Gle

ncoe A

lgebra

1

Geo

metr

ic M

ean

sA

mis

sin

g t

erm

or

term

s betw

een

tw

o n

on

con

secu

tive t

erm

s in

ageom

etr

ic s

equ

en

ce a

re c

all

ed

geo

metr

ic m

ea

ns.In

th

e s

equ

en

ce 1

0,20,40,80,…

,th

egeom

etr

ic m

ean

betw

een

10 a

nd

40 i

s 20.Y

ou

can

use

th

e f

orm

ula

an

5a

1?

rn2

1to

fin

d a

geom

etr

ic m

ean

. Fin

d t

he g

eo

metr

ic m

ea

n i

n t

he s

eq

uen

ce 6

,,

150.

In t

he s

equ

en

ce,a

1=

6 a

nd

a3

= 1

50.T

o f

ind

a2,you

mu

st f

irst

fin

d r

.

an

5a

1?

rn2

1F

orm

ula

for

the n

th t

erm

of

a g

eom

etr

ic s

equence

a3

5a

1?

r3 2

1n

53

150

56 ?

r2a

35

150 a

nd a

15

6

5D

ivid

e e

ach s

ide b

y 6

.

25

5r2

Sim

plif

y.

65

5r

Take t

he s

quare

root

of

each s

ide.

If r

55,th

e g

eom

etr

ic m

ean

is

6(5

) or

30.If

r5

25,th

e g

eom

etr

ic m

ean

is

6(2

5)

or

230.

Th

ere

fore

th

e g

eom

etr

ic m

ean

is

30 o

r 2

30.

Fin

d t

he g

eo

metr

ic m

ea

ns i

n e

ach

seq

uen

ce.

1.

4,

,16

2.

12,

,108

3.

28,

,2

128

68

636

632

4.

180,

,20

5.

22,

,2

98

6.

600,

,150

660

614

6300

7.

,,

8.

,,

9.

2,

,2

66

6

10.14,

,11.

,,10

12.

2,

,2

54

62

66

6

13.2.3

,,9.2

14.

2137.7

,,

215.3

15.

25.1

,,

2127.5

64.6

645.9

625.5

16.

,,

17.

215,

,2

18.

8,

,320,0

00

66

36

1600

3} 1

6

3 } 5

3} 3

2

3 } 8

5 } 2

2 } 3

5 } 8

2 } 7

3 } 4

1 } 8

1 } 8

15

} 16

3 } 5

1} 3

2

1 } 2

1} 1

6

1 } 4

6r2

}6

150

}6

Stu

dy G

uid

e a

nd I

nte

rven

tion

(c

onti

nued)

Geo

metr

ic S

eq

uen

ces

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D__

___

10-7

10-7

Example

Example

Exercises

Exercises

Answers (Lesson 10-7)

Page 20: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A21 Glencoe Algebra 1

An

swers

Skil

ls P

racti

ce

Geo

metr

ic S

eq

uen

ces

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-7

10-7

©G

lencoe/M

cG

raw

-Hill

617

Gle

ncoe A

lgebra

1

Lesson 10-7

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s g

eo

metr

ic.

1.

9,17,25,33,…

no

2.

4,12,36,108,…

ye

s

3.

2320,

280,

220,

25,…

ye

s4.

275,

260,

245,

230,…

no

5.

64,

232,16,

28,…

ye

s6.

26.5

,21,15.5

,10,…

no

Fin

d t

he n

ex

t th

ree t

erm

s in

ea

ch

geo

metr

ic s

eq

uen

ce.

7.

2,

24,8,

216,…

8.

22,

26,

218,

254,…

32,

264,128

2162,

2486,

21

45

8

9.

2960,480,

2240,120,…

10.

7290,2430,810,270,…

260,30,

215

90,30,10

11.

232,

216,

28,

24,…

12.

6144,1536,384,96,…

22,

21,

20.5

24,6,1.5

Fin

d t

he n

th t

erm

of

ea

ch

geo

metr

ic s

eq

uen

ce.

13.a

15

2,n

54,r

52

22

16

14.

a1

53,n

55,r

52

48

15.a

15

6,n

53,r

58

38

416.

a1

52

5,n

54,r

59

23

64

5

17.a

15

10,n

53,r

512

14

40

18.

a1

54,n

54,r

52

82

20

48

Fin

d t

he g

eo

metr

ic m

ea

ns

in e

ach

seq

uen

ce.

19.8,

,72

62

420.

75,

,3

61

5

21.

22,

,2

128

61

622.

2112,

,2

76

28

23.324,

,4

63

624.

1.5

,,24

66

©G

lencoe/M

cG

raw

-Hill

618

Gle

ncoe A

lgebra

1

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s g

eo

metr

ic.

1.

3,12,48,192,…

ye

s2.

2,17,32,47,…

no

3.

2200,

2135,

270,

25,…

no

4.

2220,

2110,

255,

227.5

,…

ye

s

5.

2992,248,

262,15.5

,…

ye

s6.

220,

250,

2125,

2312.5

,…

ye

s

Fin

d t

he n

ex

t th

ree t

erm

s in

ea

ch

geo

metr

ic s

eq

uen

ce.

7.

24,

220,

2100,

2500,…

8.

7,

221,63,

2189,…

22500,

212,5

00,

262,5

00

567,

21701,5103

9.

26250,1250,

2250,50 …

10.

50,70,98,137.2

,…

210,2,

20.4

192.0

8,268.9

12,376.4

768

11.5,

24,3.2

,2

2.5

6 …

12.

,,

,,…

2.0

48,

21.6

384,1.3

1072

,,

Fin

d t

he n

th t

erm

of

ea

ch

geo

metr

ic s

eq

uen

ce.

13.a

15

6,n

55,r

53

14.

a1

52

9,n

56,r

52

15.

a1

58,n

53,r

52

11

48

62

28

89

68

16.a

15

50,n

57,r

53

17.

a1

52

5,n

53,r

51.5

18.

a1

57,n

55,r

50.5

36,4

50

211.2

50.4

375

Fin

d t

he g

eo

metr

ic m

ea

ns

in e

ach

seq

uen

ce.

19.4,

,256

63

220.

28,

,2

392

65

621.

2,

,0.5

61

22.

220,

,2

1.2

56

523.

,,

624.

,,

6

MA

GA

ZIN

E S

UB

SC

RIP

TIO

NS

Fo

r E

xercis

es

25 a

nd

26,u

se t

he f

oll

ow

ing

in

form

ati

on

.

Th

e m

an

ager

of

a t

een

magazi

ne

wan

ts t

o in

crea

se s

ubsc

rip

tion

s by a

t le

ast

6%

each

yea

rfo

r th

e n

ext

thre

e yea

rs t

o k

eep

th

e co

mp

an

y o

per

ati

ng a

t a p

rofi

t.S

ubsc

rip

tion

s fo

r 2003

are

17,5

00.

25.D

eter

min

e th

e m

inim

um

nu

mber

of

subsc

rip

tion

s th

e sa

les

team

mu

st s

ell

for

the

yea

rs2004,2005,an

d 2

006.

18,5

50;

19,6

63;

20,8

43

26.S

up

pos

e th

e m

an

ager

wan

ts t

o in

crea

se t

he

subsc

rip

tion

s to

35,0

00.H

ow l

ong w

ill

itta

ke

to r

each

th

is g

oal

if s

ubsc

rip

tion

s in

crea

se a

t 6%

per

yea

r?ab

ou

t 12 y

r1 } 52

} 25

1 } 2

3 } 16

3} 6

43 } 4

16

} 729

8} 2

43

4 } 81

2} 2

71 } 9

1 } 61 } 4

Pra

cti

ce (

Avera

ge)

Geo

metr

ic S

eq

uen

ces

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-7

10-7

Answers (Lesson 10-7)

Page 21: Answers (Lesson 10-1) - Merrimack High School...1 3 x 1 8 The degree of a quadratic function is 2, and the exp onents are positive. Graphs of quadratic ... Sample answer:The vertex

© Glencoe/McGraw-Hill A22 Glencoe Algebra 1

Readin

g t

o L

earn

Math

em

ati

cs

Geo

metr

ic S

eq

uen

ces

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D_____

10-7

10-7

©G

lencoe/M

cG

raw

-Hill

619

Gle

ncoe A

lgebra

1

Lesson 10-7

Pre

-Act

ivit

yH

ow

ca

n a

geo

metr

ic s

eq

uen

ce b

e u

sed

to

desc

rib

e a

bu

ng

ee j

um

p?

Read

th

e i

ntr

od

uct

ion

to L

ess

on

10-7

at

the t

op

of

page 5

67 i

n y

ou

r te

xtb

ook

.

How

can

you

fin

d t

he d

ista

nce

of

the f

ifth

bou

nce

?

Mu

ltip

ly 3

3ft

by

.

Read

ing

th

e L

ess

on

1.

Su

pp

ose

you

are

giv

en

th

e f

irst

th

ree t

erm

s of

a g

eom

etr

ic s

equ

en

ce a

nd

wan

t to

fin

d t

he

next

thre

e t

erm

s.

a.

Wh

at

shou

ld y

ou

do t

o f

ind

th

e c

om

mon

rati

o?

Div

ide t

he s

eco

nd

term

of

the s

eq

uen

ce b

y t

he f

irst,

or

div

ide t

he t

hir

dte

rm b

y t

he s

eco

nd

.

b.

Wh

at

shou

ld y

ou

do a

fter

you

fin

d t

he c

om

mon

rati

o?

Beg

inn

ing

wit

h t

he t

hir

d t

erm

of

the s

eq

uen

ce

,m

ult

iply

by t

he

co

mm

on

rati

o.M

ult

iply

th

e r

esu

ltin

g p

rod

uct

by t

he c

om

mo

n r

ati

o,an

dre

peat

this

ste

p w

ith

th

e n

ew

pro

du

ct.

2.

Su

pp

ose

you

are

ask

ed

to g

ive a

n e

xam

ple

of

a g

eom

etr

ic s

equ

en

ce.A

re t

here

an

yre

stri

ctio

ns

on

th

e t

erm

s of

the s

equ

en

ce o

r th

e c

om

mon

rati

o r

? E

xp

lain

.

Yes;

the s

eq

uen

ce c

an

no

t b

eg

in w

ith

0,an

d t

he c

om

mo

n r

ati

o c

an

no

t b

eeq

ual

to 0

or

1.

3.

You

can

use

th

e f

orm

ula

for

the n

th t

erm

of

a g

eom

etr

ic s

equ

en

ce t

o f

ind

an

y t

erm

in

th

ese

qu

en

ce.W

hat

info

rmati

on

do y

ou

need

in

ord

er

to u

se t

he f

orm

ula

?

Yo

u n

eed

to

kn

ow

th

e f

irst

term

of

the s

eq

uen

ce

,th

e c

om

mo

n r

ati

o,an

dw

here

th

e t

erm

yo

u a

re i

nte

reste

d i

n f

alls i

n t

he s

eq

uen

ce

.

4.

Con

sid

er

the g

eom

etr

ic s

equ

en

ce 3

,6,12,24,48,…

.H

ow

man

y g

eom

etr

ic m

ean

s are

there

for

each

pair

of

term

s? W

hat

are

th

ey?

a.

3 a

nd

12

on

e;

6b

.3 a

nd

24

two

;6 a

nd

12

Help

ing

Yo

u R

em

em

ber

5.

To r

em

em

ber

an

id

ea,it

can

help

if

you

exp

lain

it

to s

om

eon

e e

lse.S

up

pose

a f

rien

dth

ink

s th

at

the f

orm

ula

for

the n

th t

erm

of

a g

eom

etr

ic s

equ

en

ce s

hou

ld b

e a

n5

a1r

n

rath

er

than

an

5a

1rn

21.H

ow

wou

ld y

ou

exp

lain

wh

y i

t sh

ou

ld b

e a

n5

a1r

n2

1?

Sam

ple

an

sw

er:

Th

e s

eq

uen

ce s

tart

s w

ith

a1.T

he s

eco

nd

term

is

a2

5a

1r1

.Th

e t

hir

d t

erm

is a

35

a1r

2,an

d s

o o

n.T

he e

xp

on

en

t fo

r r

is o

ne

less t

han

th

e t

erm

nu

mb

er.

So

an

5a

1r

n2

1.

3 } 43 } 4

©G

lencoe/M

cG

raw

-Hill

620

Gle

ncoe A

lgebra

1

Co

nverg

en

ce

,D

iverg

en

ce

,an

d L

imit

s

Imagin

e t

hat

a r

un

ner

run

s a m

ile f

rom

poin

t A

to p

oin

t B

.B

ut,

this

is

not

an

ord

inary

race

! In

th

e f

irst

min

ute

,h

e r

un

s on

e-h

alf

mil

e,re

ach

ing p

oin

t C

.

In t

he n

ext

min

ute

,h

e c

overs

on

e-h

alf

th

e r

em

ain

ing d

ista

nce

,or

mil

e,

reach

ing p

oin

t D

.In

th

e n

ext

min

ute

he c

overs

on

e-h

alf

th

e r

em

ain

ing

dis

tan

ce,or

mil

e,re

ach

ing p

oin

t E

.

In t

his

str

an

ge r

ace

,th

e r

un

ner

ap

pro

ach

es

close

r an

d c

lose

r to

poin

t B

,bu

t n

ever

gets

th

ere

.H

ow

ever

close

he i

s to

B,th

ere

is

stil

l so

me d

ista

nce

re

main

ing,an

d i

n t

he n

ext

min

ute

he c

an

cover

on

ly h

alf

of

that

dis

tan

ce.

Th

is r

ace

can

be m

od

ele

d b

y t

he i

nfi

nit

e s

equ

en

ce

,,

,,…

.

Th

e t

erm

s of

the s

equ

en

ce g

et

close

r an

d c

lose

r to

1.A

n i

nfi

nit

e s

equ

en

ce

that

gets

arb

itra

rily

clo

se t

o s

om

e n

um

ber

is s

aid

to c

on

verg

eto

th

at

nu

mber.

Th

e n

um

ber

is t

he l

imit

of

the s

equ

en

ce.

Not

all

in

fin

ite s

equ

en

ces

con

verg

e.T

hose

th

at

do n

ot

are

call

ed

div

erg

en

t.

Writ

e C

if

the s

eq

uen

ce c

on

verg

es

an

d D

if

it d

iverg

es.

If t

he

seq

uen

ce c

on

verg

es,

ma

ke a

rea

son

ab

le g

uess

fo

r i

ts l

imit

.

1.

2,4,6,8,10,…

D2.

0,3,0,3,0,3,…

D

3.

1,

,,

,,…

C,0

4.

0.9

,0.9

9,0.9

99,0.9

999,…

C,1

5.

25,5,

25,5,

25,5,…

D6.

0.1

,0.2

,0.3

,0.4

,…

D

7.

2,2

,2

,2

,…

C,3

8.

6,5

,5

,5

,5

,…

C,5

9.

1,4,9,16,25,…

D10.

21,

2,

2,

2,

2,…

C,0

11.C

reate

on

e c

on

verg

en

t se

qu

en

ce a

nd

on

e d

iverg

en

t se

qu

en

ce.G

ive t

he

lim

it f

or

you

r co

nverg

en

t se

qu

en

ce.

An

sw

ers

will

vary

.S

am

ple

an

sw

er:

1,

,,

,,…

co

nverg

en

t,0

1,5,25,125,625,…

div

erg

en

t

1} 8

11

} 27

1 } 91 } 3

1 } 5

1 } 4

1 } 3

1 } 2

1 } 5

1 } 4

1 } 3

1 } 2

15

} 16

7 } 8

3 } 4

1 } 4

1 } 5

1 } 4

1 } 3

1 } 2

15

} 16

7 } 8

3 } 4

1 } 2

D(3

:02 P

.M.)

C(3

:01 P

.M.)

B (?)

E(3

:03 P

.M.)

A(3

:00 P

.M.)

0 m

ilem

ile1 – 2

mile

3 – 4m

ile7 – 8

1 m

ile

1 } 8

1 } 4

En

rich

men

t

NA

ME

______________________________________________

DA

TE

____________

PE

RIO

D__

___

10-7

10-7

Answers (Lesson 10-7)