Key
Features
Features
Growth or Decay?
(Part 1)
(Part 1)
Growth or Decay?
(Part 2)
(Part 2)
Percent Rate
Word Problems
100
Exponential functions are written in what form?
y=a(b)x
100
How do you know if an exponential function represents decay?
less than 1
100
A bunny population doubles every year. If the starting population is 10, increase at 9%, how many will you have after 4 years? What is initial? What is the rate?
initial = 10
rate = 0.09
After 4 years = 14.11 or 14
y=10(1+0.09)4
100
What is the percent growth/decay rate?
y=5(0.6)^x
40%
100
2243
200
What does b represent in an exponential function when 0<b<1?
The decay factor
200
How do you know if an exponential function represents growth?
If b is greater than 1
200
f(x)=4(0.9)x
Does this function represent exponential growth or decay? Identify the growth/decay rate as a decimal and as a percent.
Decay
0.1
10%
200
What is the percent growth/decay rate?
y=2(1.3)^x
30%
200
What will be the cost in 17 years? Round to the nearest dollar.
$32,313
300
In an exponential function, "a" represents _____________?
The initial value
300
Growth or Decay?
y=3.5(3)x
Growth
300
f(x)=a(1.07)x
Does this function represent exponential growth or decay? Identify the growth/decay rate as a decimal and as a percent.
Exponential Growth
0.07
7%
300
What is the percent growth/decay rate?
y=(0.01)^x
99%
300
16,941 people
400
What's the value of b?
b = 2
400
Growth or Decay?
y=9(0.8)x
Decay
400
Does the graph represent exponential growth or decay? What is the value of a?
Exponential Growth
a = 2400
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 does x represent in the equation
y=750(1.43)4
4 years
500
Growth or Decay?
y=2x
Growth
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? Round to the nearest dollar.
530,000(1.05)6 =$710,251
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? Round to the nearest cent.
$579.64