bell work 1.label the quadrants 2.plot the points a(-2,1), b(4,1), c(4,-3), and d(-2,-3) 3. find the...
TRANSCRIPT
Bell Work1. Label the quadrants2. Plot the points A(-2,1),
B(4,1), C(4,-3), and D(-2,-3) 3. Find the area and perimeter
of the figure Q1
Q4Q3
Q2
A(-2,1) •
D(-2,-3) • • C(4,-3)
• B(4,1) Area = 4 × 6 =24 units2
Perimeter = 4 + 4 + 6 + 6 = 20 units
•Skills Check!When you finish turn your paper over and
put it in the corner of your desk. Silent read or work on other homework.
No talking.
Evaluating a Function
Evaluate the function y = 5x when x = 7.
y = 5x
= 5(7) Substitute 7 for x.
= 35 Multiply.
Evaluating a Function
Fundraising
Your soccer team is selling glow sticks to raise money. The team paid $50 for a case of 48 glow sticks andsells each glow stick for $3. How many glow sticksdoes the team need to sell to start earning a profit?Use the function rule P = 3g – 50, where P is the profit
in dollars and g is the number of glow sticks your teamsells.
SOLUTION
Make a table to determine how many glow sticks yoursoccer team needs to sell to start earning a profit.
ANSWER
Your soccer team needs to sell 17 glow sticks.
Evaluating a Function
KEY TERMS• Function – a relationship where one
thing depends on another• Function Table – a way to organize the
input numbers, output numbers, and the function rule
• Domain – set of input values (x)• Range – set of output values (y)• Linear Equation – graph of a straight
line• Ordered Pair – a pair of numbers used
to locate a point in a coordinate system
Make a Function Table
• Your test grades for the semester are a 95%, 80%, 63%, 97%, 95%
Input Output
Domain Range
95%
63%
80%
97%
A
B
A
D
95% A
Make a Function Table
• Suppose you earn $5 each week. Make a function table that shows your total earnings after 1, 2, 3, and 4 weeks.
Input(x)
Function Table
Output(y)
# of wks y=5x total
Domain Range
1
3
2
4
5(1)
5 (2)
5 (4)
5(3)
5
10
20
15
Sometimes we use “function machines” to determine rules of functions.
Practice using a Function
The rule of the functionInput
Output
12
8
+ 4
Input-Output Machines
• We can think of equations as input-output machines. The x-values being the “inputs” and the y-values being the “outputs.”
• Choosing any value for input and plugging it into the equation, we solve for the output.
y = -2x + 5 y = -2(4) + 5
y = -8 + 5y = -3
x = 4 y = -3
Function Tables
In (x) Out (y)
The input is a number going in.
Let’s imagine this equation y = x+ 5
The output is the result of applying the rule ( + 5)
+ 5 is the rule
Function Tables
In (x) Out (y)
– 2 3
– 1 4
0 5
1 6
2 7
3 8
The input is a number going in.
Let’s imagine this equation y = x+ 5
The output is the result of applying the rule ( + 5)
+ 5 is the rule
Making an Input-Output Table horizontally
Make an input-output table for the function y = x – 1.3 using the domain 0, 1, 2, and 3. Then state the range of the function.
SOLUTION
The range of the function is the set of outputs –1.3,– 0.3, 0.7, and 1.7.
You try:1. Make an input-output table for the function y = 2x + 2 using the
domain –2, – 1, 0, 1, and 2. Then state the range of the function.
Input x –2 –1 0 1 2
Substitution y = 2(-2) + 2 y = 2(-1) + 2 y = 2(0) + 2 y = 2(1) + 2 y = 2(2) + 2
Output y -2 0 2 4 6
SOLUTION
The range of the function is the set of outputs –2, 0, 2, and 6.
Function Tables
In Out
4 97 12
10 15
Find the pattern and fill in the numbers then write the function rule.
Function rule: y= x + 5
13 1816 2119 24
Function Tables
In Out
7 216 1854 12
96
15
3
2
Function rule: y = 3x
Find the pattern and fill in the numbers then write the function rule.
Function Tables
In Out
20 1418 121614
64
108
1210
Function Rule: y= x – 6
Find the pattern and fill in the numbers then write the function rule.
Function Tables
In Out
28 724 62016
32
54
128
Function rule: y = x ÷ 4
Find the pattern and fill in the numbers then write the function rule.
Function Tables
In Out
7 2010 231316
3235
2629
1922
Function rule: y = x + 13
Find the pattern and fill in the numbers then write the function rule.
Practice:Worksheet