1. 7. The tuition at a private college can be modeled by the equation ,
Exponential Growth and Decay
If you know the rate of change, r, you can find the growth factor or decay factor by using the equation
Growth factors are going to be ____________ than 100% (or ____________ than 1).
When you multiply by a number larger than 1 over and over, your answer GROWS!
Decay factors are going to be ____________ than 100% (or ____________ than 1).
When you multiply by a number smaller than 1 over and over, your answer SHRINKS (or DECAYS)!
For each annual rate of change, find the corresponding growth or decay factor.
7. The tuition at a private college can be modeled by the equation ,
where y is the number of years since 2000.
The tuition in the year 2000 was $30,000. The growth rate of tuition is 107%.
A. True A. True
B. False B. False
Perhaps do some easy evaluating during a warm-up, then tie it into evaluating into an exponential function with a STORY!
larger
larger
smaller
smaller

2. 8. What is the decay rate in the function ? A. 0.20 C. 0.52
B D
9. A student noticed that the value of f(2) is 10% less than f(1).
He also noticed that f(3) is 10% less than f(2). Which is true?
A. f is a linear function with slope C. f is an exponential function with base
B. f is a linear function with slope D. f is an exponential function with base
10. A population begins with 1,200 individuals and grows at a rate of 10% per year.
Which function describes the population? A. B. C.
11. The population of a certain animal species decreases at a rate of 3.5% per year.
You have counted 80 of the animals in the habitat you are studying.
A. Write a function that models the change in the animal population.
B. Use a graphing calculator to graph the function.
Estimate the number of years until the population first drops below 15 animals.