Exponential Growth and Decay Notes.notebook
Growth and Decay Formula
N = New Population Size (after growth)
N0 = Original Population Size
b = (1 + rate) growth factor
(1­ rate) decay factor
d = time it takes to double, triple, etc
t = how long it grows for
Write an exponential function to model each situation. Find the value of the function after 5 years.
A population of 250 frogs increases at an annual rate of 22%. Exponential Growth and Decay Notes.notebook
Write an exponential function to model each situation. Find the value of the function after 5 years.
A stock priced at $35 increases at a rate of 7.5% per year.
Write an exponential function to model each situation. Find the value of the function after 5 years.
A $17,500 delivery van depreciates 11% each year.
Exponential Growth and Decay Notes.notebook
Write an exponential function to model each situation. Find the value of the function after 5 years.
A population of 115 cougars decreases 1.25% each year.
The population of the United States in 1994 was about 260 million, with an average annual rate of increase of about 0.7%.
a.) Suppose this rate of growth continues what would the population be in 2020?
Exponential Growth and Decay Notes.notebook
Suppose the population of a certain endangered species decreases at a rate of 3.5% per year. You have counted 80 of these animals in the habitat you are studying.
a.) Predict the number of animals that will remain after 10 years.
b,) At this rate, after how many years will the population drop below 15 animals?
Suppose you are buying a new car. You want the car that will be the most after five years. Of the three choices listed below, which car should you buy?
Car
Original Price
Expected Depreciation
1
2
3
$12,455
$15,320
$17,005
10%
12%
15%