Key Features Expon. f(x)'s
Growth or Decay
Growth or Decay
Percent Rate
Word Problems
100
If, y=a(b)x , What do the varaibles 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 less than 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 factor for the function f(x)=2(3)x
y-intercept=2
growth factor= 3
200
Mr. Bowers purchased a car for 26,400 and every year it depreciates by 12%. What can he expect the value of his car to be after 3.5 years?
f(x)=26400(.88)3.5=$16,876.92
200
In exponential functions, when b>1 this will cause an exponential growth or decay?
Exponential growth
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
What is the y-intercept and range?
y-intercept = (0, 1)
range y > 0
300
f(x)=2(.93)x
Does this functions represent exponential growth or decay? What is the percent growth/decay rate?
Exponential Decay
Multiplier .93
1-.93 = .07, which means 7% rate
Check (1-.07)= (.93)
300
f(x)=-4(1.07)x
Does this functions represent exponential growth or decay? What's the percent growth/decay factor?
Exponential Growth. 7%.
300
What is the percent growth/decay rate?
y=(0.01)^x
99% Decay
300
16,941 people
400
What's the multiplier?
b=2
400
Write an equation to represent a town with an initial population of 1,400 people and an annual growth rate of 1.25%
f(x)= 1400 (1 + 0.0125)x
f(x)= 1400(1.0125)x
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? What is the multiplier (common ratio)? 
Decay (.50) or
1/2
500
What is the difference between linear functions and Exponential functions
Linear has a constant difference or rate of change
Exponential has a multiplier or common ratio
500
Find the equation for:
Passes through the points (1, 10.5) and (2, 31.5)
y=3.5(3)x
500
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
500
What is the percent growth/decay rate?
y=60(1.33)^x
33% Growth
500
If you put $500.00 into an account and the account earns 3% interest each year. How much will be in the account after 5 years?
$579.64