Algebra ISection 7-5

Exponential Functions

- growth functions: increase from left to right

integer values for base

- decay functions: decrease from left to right

fraction values for base

- domain: all real numbers - range:

look at pictureeither all positive numbers or

all negative numbers

Graphing Exponential Functions

Step 1) find y when x =0

Step 2) determine if function is growth or

decay

Step 3) sketch

5. DEPRECIATION

The function V = 22,000 ● 0.82t

models the depreciation of the value of a new car that

originally cost $22,000. V represents the value of the

car and t represents the time in years from the time the

car was purchased. What is the value of the car after

one year?

Identify Exponential Behavior

- look for regular intervals of the x-values

counting by: 1’s, 2’s, 5’s, …

- look for common factor (multiply or divide)

of the y-values

Determine whether the set of data shown below displays exponential behavior. Write yes or no, and explain why or why not.

6. X 0 3 6 9 12 15

Y 12 16 20 24 28 32

Determine whether the set of data shown below displays exponential behavior. Write yes or no, and explain why or why not.

7. X 0 10 20 30

Y 10 25 62.5 156.25

Homework

Worksheet 7-5

Chapter 7 Test Friday 1/30