For more exercises, see Extra Skill and Word Problem Prac: it

0 rractice by Example Copy each graph. Label each section ofthe graph.

Example 1

(page 252)

1. )

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Time

Time Time

Sketch a graph of each situation. Label each section.

5. hours of daylight over the course of one vear

6. your distance from the ground as you ride a Ferris wheel for five minutes

7. your pulse rate as you watch a scary movre

8. your walking speed during five minutes between classes

9. eoeking You turn on your oven to bake a casserole. Which graph bestrepresents the oven temperature over time? Explain your choice.

Time

4.

J

Example 2

(page 253)

Example 3

(page 253)

Time Time

O opply Your skills f;* fO. Sfeatgrer The graph shows the barometric pressure in Pittsburgh,Pennsylvania. during ablizzard. Describe what happened to the pressuredurins the storm.

Blizzard of 1993

a

7 e.r,r. 7 p.u.

TimeSouRcE: Purdue Weather Processor

11. Sketch graphs of each situation. Are the graphs the same? Explain.a. Your speed as you travel from the bottom of a ski slope to the top.b. Your speed as you travel from the top of a ski slope to the bottom.

7 a..u

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254 Chapter 5 Graphs and Functions O- ,:e

IvrvesfiqattngY = wx + h

c.y:x-1

You can use a graphing calculator to explore the graph of an equation in the

form y : mx + b. For this activity, use a standard screen by pressing

ffi0.1. Graph these equations on the same screen. Then complete each statement.

t:x+7 y:2x-r1 Y:lx+t

ffi p,.c.s,tnvestigate ancffiffin:x

a. The graph of ? is closest to the y-axis.

b. The graph of ? is closest to the r-axis.

2. Match each equation with the best choice for its graph.

A.y:t"-1 B.Y:5x-1-

generalize how changingthe coefficients of a

function affects its graph\.A.34 Write t

cf a line, 9irand the coocoint on tht

u. A.35 Write:f a line, gi':oordinates:n the line.

u A.37 Deter:f a line, gt

:quation ir

For: Graphing calcu :*;:,procedures

Web Code: ate-210r

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3. How does changin g m affect the graph of an equation in the form y : mx * b?

4. Graph these equations on the same screen.

y:2x+1 Y:-2x+IHow does the sign of m affect the graph of an equation?

5. Graph these equations on the same screen.

y:2x+I y:2x-2 Y:2x+ZWhere does the graph of each equation cross the y-axis? (Hint: rJse the

feature to better see the points of intersection')

6. Match each equation with the best choice for its graph.

:-.i.,:

A.y:1.*-s B.y:+*

II.

C.y:lx+3

7. How does changing the value of b affect the graph of an equation in the

form Y : mx -l b?

8. you can change the appearance of a graph by changing its scale in the ffiEscreen' Describe how the graph of y = 2x + 1 changes from its appearance on a

standard screen using the following values for Xmin, Xmax,Ymin, and Ymax.

a. Xmin = -5 Ymin = -10Xmax=5 Ymax=10

b. Xmin = -10 Ymin = -5Xmax = 10 Ymax = 5

316 Activity Lab Investigating y: mx + b

EXERCISES For more exercises, see Extra Skill and Word Problem Prar::t

ffL PraetEee bv Exa*:ple Find the slope and yiintercept of each equation.

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Example I(page 318)

Example 2

(page 318)

Example 3

(page 318)

Example 4(page 319)

Example 5

(page 319)

1.y:-2x+\4.Y:5x+87'Y:-x-J

L0.m:'g,U:,13.m:0,b:L16.m:0.3,b:4re. m: -!,u : -?

12.y:-)x+25."y:5x+I8.y: -0.7x-9

42.y+L*:o45.2y - 6:3x48.y:(2-a)x+a

lY:*-tr6.v: -4*e.y: -tr* - s

43.y-s*:+.46. -2y : [(J - ,rr.

49.2y -r 4n : -6.t

Write an equation of a line with the given slope and y-intercept.

ll.m:3,b:? 12.m:Z,r:t14.m: *1.,b: -6 15.m: _3,U: t17.m : 0.4,b : 0.6 Lg.m : -1,b :+20.m:-1,U:tr 2r.m:8,u:?

Write the slope-intercept form of the equation for each line.

Use the slope and y-intercept to graph each equation.

28.y:$x+a 29.y:?*-t 30.y: -5x*2 3r.y:2x-:32.y:aa4 33.y:*x*2 34.y:4x*3 35.y:-jr36.y :?* - z 37.y : -?* * 2 s8.t : -!x + + 3e.y :-0-<,

40. fr*tail S;r€el* A music store is offering a coupon promotion on its CDs. Th.regular price for CDs is $14. With the coupon, customers are given $4 off :.-.total purchase. The equation t : 14c - 4, where c is the number of CDs .- -r is the total cost of the purchase, models this situation.a. Graph the equation.b. Find the total cost for a sale of 6 CDs.

Find the slope and y-intercept of each equation.

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p oon,.l v{isl'Skiilr

4I.y-2:-3x44'Y:3x-947.y-d:cx

320 Chapter 6 Linear Equations and Their Graphs $r- :;