Functions

AnimalsAn armadillo sleeps 19

hours each day. Complete a function table and write an equation using two

variables to show the relationship between the

number of hours h an armadillo sleeps in d

days.

AnswerInput

Number of Days

Function Rule

Multiply by 19

OutputNumber of hours of

Sleep1 1 x 19 19

2 2 x 19 38

3 3 x 19 57

4 4 x 19 76

Equation

h = 19d

Botanist A botanist discovers that a certain

species of bamboo grows 4 inches each hour.

A. Write an equation using two

variables to show the relationship between the growth g in inches of this bamboo plant in h hours.

B. Use your equation to explain how to find the growth in inches of this species of bamboo after 6 hours.

Answers

A. g = 4h

B. 24 inches

PizzaA pizza shop sells 25 pizzas each hour.

At the same rate, find the number of

pizza sold after 1, 2, 3, and 4 hours.

Make a function table. Write an equation using two variables

to show the relationship between the

number of hours h and p the number of pizzas

sold.

AnswersX 25x y

1 25 * 1 25

2 25 * 2 50

3 25 * 3 75

4 25 * 4 100

Equation

p = 25 h

Typing►Suppose you can type 60 words per

minute. What is the total number of words typed after 5, 10, 15, and 20 minutes.

►Make a function table. ►Write an equation using two variables

to show the relationship between the number of words typed w and m minutes.

Function TableX 60 x Y

5 60 * 5 300

10 60 * 10 600

15 60 * 15 900

20 60 * 20 1,200

Equation

w= 60m

Cell Phones►Verizon charges a customer $40 for

each month of service.►Write an equation using two variables

to show the relationship between the total amount charged c after m months of

service.►Use the equation to EXPLAIN how to

find the total cost for 6 months of cell phone service.

Answers c = 40m

$240 – Substitute m with 6 in the equation c = 40m.

Running►The average marathon running speed

is 5.5 miles per hour. Find the number of miles run after 1, 2, 3, and 4 hours at this rate.

►Make a function table to show the number of miles after 1, 2, 3, and 4 hours.

►Write an equation using two variables to show the relationship between the number of miles m and the h hours.

Function Tablex 5.5x y1 5.5 * 1 5.52 5.5 * 2 113 5.5 * 3 16.54 5.5 * 4 22

Equation

m = 5.5h

Exit Ticket 1. The function rule is only true

if . .

2. How do you know if a relation is a function?