How do I know if an exponential function is exponential decay from an equation?
If the b is in between 0 and 1
A bunny population doubles every 6 months. If the starting population is 10, what is the growth factor?
growth rate = 2
What is the percent growth/decay rate?
y=5(0.5)^x
50%

2243
In an environment with unlimited resources and no predators, a population tends to grow by the same percentage each year. Should a linear or exponential function be used to model such a population? Why?
An exponential because it is changing at a constant rate. The same percentage does not mean it will be changing by the same number each year, which is what a linear model suggests.
The breakdown of a sample of a chemical compound is represented by the function p(t) = 300(.5)t, where p(t) represents the number of milligrams of the substance and t represents the time, in years. In the function p(t), explain what 0.5 and 300 represent.
0.5 represents the rate of decay and 300 represents the initial amount of the compound.
In exponential functions, when the number inside the parentheses is greater than 1, this will cause an exponential growth or decay?
Exponential growth
What is the percent growth/decay rate?
y=5(1.3)^x
30%

What will be the cost in 17 years?
$32,313.27
A population has size 5000 at time t = 0, with t in years. a) If the population decreases by 100 people per year, find a formula for the population, P, at time t. b) If the population decreases by 8% per year, find a formula for the population, P, at time t.
a) P = 5000 - 100t b) P = 5000(.92)^t
f(x)=a(.93)x
Does this functions represent exponential growth or decay? What is the percent growth/decay rate?
Exponential Decay
r = 7%
f(x)=37(1.07)x
Does this function represent exponential growth or decay? What's the factor in percentage?
Exponential Growth. 7%
What is the percent growth/decay rate?
y=(0.01)^x
99%

16,941 people
A boat purchased for $20000 depreciates at a rate of 5% per year. What will the value of the boat be in 10 years.
$11974.74
Label the following formula:

y = final amount
a = initial amount
r = rate of growth
t = time
Does the graph represent exponential growth or decay?
Exponential Growth
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=1/2(0.7)^x
Decay. 30%
Is the function exponential growth or decay? 
Decay
The current population of polar bears is 10000 and is decreasing at a rate of 2% per year. How many polar bears will there be in 10 years.
In 10 year there will be approximately 8171 polar bears.
Ms. Wiggins purchased a car for 26,400 and every year it decays by 12%. What can she expect the value of her car to be after 3.5 years?
f(x)=26400(.88)3.5=$16,876.92
Annual sales of a fast food restaurant are $530,000 and increasing at a rate of 5%. What will the annual sales be in 6 years?
530,000(1.05)6 =$710,250.69
What is the percent growth/decay rate?
y=60(1.33)^x
33%
If you put $500.00 into an account and the account earns 3% interest. How much will be in the account after 5 years?
$579.64
A radioactive substance decays at a continuous rate of 14% per year, and 50 mg of the substance is present in the year 2009. How much will be present in the year 2019?
11.065 mg