Name: _____________________________________________ Date: __________ Period: __________
REVIEW for TEST 4.1
1. Tell whether the following graphs represent exponential growth or decay. Then write the rule for
the exponential function.
a)
a)
b)
b)
2. The table below represents an exponential growth function.
Identify the y-intercept. B) Identify the constant ratio. C) Write the
equation.
a)
x
-2
-1
0
1
f(x)
1
2
4
8
A)
B)
C)
3. Write the equation for the exponential growth function in the table.
X
1
0
-1
-2
Y
15
5
5
3
5
9
4. When given a function that describes a situation, how can you tell whether the
function represents exponential growth or decay?
5. Graph each function. State the y-intercept, constant ratio, domain, range, and asymptote.
x
A f ( x ) = 0 .75( 2
)x
B
y-int:
y-int:
r:
r:
domain:
domain:
range:
range:
asymptote:
asymptote:
1
y = 3 
 2
_
6. Find a, b and the y-intercept for f(x)=5(2)x. State the asymptote. Domain & Range.
7.. Find a, b and the y-intercept for f(x) = 2(0.5)x. State the asymptote. Domain & Range.
8. Suppose you were a Revolutionary War veteran and had the foresight to put one penny in a
bank account when George Washington became President in 1789. If the bank promised you 5%
interest on your account, how much would it be worth in 2014?
9. Ten years ago, Drew’s Mother bought a used car for $9,000. The car depreciated at a
steady rate of 20% per year. Write and solve the equation he should use to calculate C, the
current value of the car.
10. If a basketball is dropped from a height of 15 feet, the function f (x) =15(0.75)x gives the
height of the ball in feet after each bounce, where x is the bounce number. What will be the
height of the ball after the fifth bounce? Round to the nearest tenth of a foot.
11. The half-life of a radioactive substance is the average amount of time it takes for half of its
atoms to disintegrate. Suppose you started with 200 grams of a substance with a half-life of 3
minutes. How many minutes have passed if 25 grams now remain? Explain your reasoning.