Key Features Expon. f(x)'s
Growth or Decay
Growth or Decay
Percent Rate
Word Problems
100
If, y=a(bx ), what do they represent?
a=initial amount/y-intercept
b=growth/decay factor
100
How do I know if an exponential function is exponential decay from an equation?
If the b is in between 0 and 1
100
A bunny population doubles every 6 months. If the starting population is 10, how many will you have after 3 years? What is the initial population? What is the growth factor?
initial population = 10
growth rate = 2
100
What is the percent growth/decay rate?
y=5(0.5)^x
50%
100
2243
200
What is the y-intercept and growth/decay factor for the function f(x)=2(3)x
**Make sure to identify whether it is growing or decaying**
y-intercept=2
GROWTH FACTOR = 3
200
Find the exponential equation for the line that will pass through the points (0, 3.5) and (2, 31.5)
HINT: STAT Key
y=3.5(3)x
200
In exponential functions, when 0<b<1 this will cause an exponential growth or decay?
Exponential Decay
200
What is the percent growth/decay rate?
y=5(1.3)^x
30%
200
What will be the cost in 17 years?
$32,313.27
300
Write the equation for the function. What is the y-intercept and growth factor? 
y-intercept = (0, 1)
growth factor = 2
y = 2x
300
f(x)=a(.93)x
Does this functions represent exponential growth or decay? What is the percent growth/decay rate?
Exponential Decay
300
f(x)=a(1.07)x
Does this functions represent exponential growth or decay? What's the percent growth/decay rate?
Exponential Growth. 7%.
300
What is the percent growth/decay rate?
y=(0.01)^x
99%
300
16,941 people
400
What's the initial value and growth/decay factor? Then write the equation for the function.
a=5
b=2
y=5(2)x
400
Describe how to tell if a table represents a linear or an exponential function?
Draw in the "loopty loops" and see if the x and y values are increasing or decreasing by what amount.
constant rate of change = Linear
NOT constant rate of change = Exponential
400
Does the graph represent exponential growth or decay?
Exponential Growth
400
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=1/2(0.7)^x
Decay. 30%
400
Is the function exponential growth or decay? 
Decay
500
What is the difference between linear functions and Exponential functions
Linear has a constant difference
Exponential has a FACTOR
500
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
500
Annual sales of a fast food restaurant are $530,000 and decreasing at a rate of 5%. What will the annual sales be in 6 years?
530,000(0.94)6 =$365,630.98
500
What is the percent growth/decay rate?
y=60(1.33)^x
33%
500
If you put $500.00 into an account and the account earns 3% interest, compounded annually. How much will be in the account after 5 years?
$579.64