Key Features Expon. f(x)'s
Growth or Decay
Growth or Decay
Percent Rate
Word Problems
100
For the exponential function y=a(bx ), what do the variables a and b represent?
a=initial amount/y-intercept
b=multiplier/factor
100
How do I know if an exponential function is exponential decay from an equation?
Example: y = 3(0.56)x
The b-value (multiplier/factor) is between 0 and 1.
100
For the exponential function y=15(3)x, what is the factor, and does the function represent growth or decay?
Exponential Growth
Factor: 3
100
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=5(0.5)^x
Exponential Growth
50%
100
2243
200
What is the y-intercept and multiplier for the function f(x)=2(3)x
y-intercept=2
multiplier= 3
200
Do the following equations represent exponential growth, decay, or neither?
a) y=3.5(0.3)x
b) y=2(3)x
c) y=5x+6
a) Decay
b) Growth
c) Neither (It's linear! y=mx+b)
200
For an exponential function, when the b-value is greater than 1, will this cause an exponential growth or decay relationship?
Exponential growth
200
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=5(1.3)^x
Exponential Growth
30%
200
What will be the cost in 17 years?
$32,313.27
300
What is the y-intercept, and does the function represent exponential growth or decay?
y-intercept = (0, 1)
Exponential Growth
300
f(x)=2(1.13)x
Does this function represent exponential growth or decay? What is the growth/decay RATE?
Exponential Growth
Rate: 0.13 or 13%
300
f(x)=7(1.07)x
Does this functions represent exponential growth or decay? What's the percent growth/decay RATE?
Exponential Growth.
Rate: 0.07 or 7%.
300
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=(0.01)^x
Exponential Decay
99%
300
16,941 people
400
What's the y-intercept and the factor?
y-intercept: (0,5)
Factor: 2
400
f(x)=5(0.97)x
Does this function represent exponential growth or decay? What is the growth/decay RATE
Exponential Decay
Rate: 0.03 or 3%
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
Exponential Decay
30%
400
Is the function exponential growth or decay? 
Decay
500
What is the difference between linear functions and Exponential functions
Linear - Addition
Exponential - Multiplication
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 increasing at a rate of 5% per year. What will the annual sales be in 6 years?
530,000(1.05)6 =$710,250.69
500
Is this exponential growth or decay?
What is the percent growth/decay rate?
y=60(1.33)^x
Exponential Growth
33%
500
If you put $500.00 into an account and the account earns a 3% yearly interest rate. How much will be in the account after 5 years?
Round the nearest cent!
$579.64