Exponential Functions Review

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth
• Decay

What type of function is f(x)=2(1/7)^x ?

• Exponential Growth
• Linear
• Exponential Decay
• None of the Abovee

A new savings account is opened with $400 and gains 3% every year. What is the exponential function?

• f(x)=400(1+3)^x
• f(x)=400(1-0.03)^x
• f(x)=400(1+0.03)^x
• f(x)=400(0.03)^x

Which function models this table?

• $f\left(x\right)=2\cdot4^x$

• $f\left(x\right)=4^x$

• $f\left(x\right)=4\cdot2^x$

• $f\left(x\right)=8^x$

A population of 2200 beetles is too large to sustain and decreases in population each month at a rate of 5%. How would you write your decay factor, b?

• -5
• -.05
• .95
• .05

Write an equation that models the following situation:
Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x
• y=6(1+14)^x
• y=6(1.14)^x
• y=6(0.86)^x

Given the following exponential function, identify whether the change represents growth or decay, and determine the percentage rate of increase or decrease.

 $y=72(0.913)^x$  

• Growth by 91.3%

• Decay by 91.3%

• Growth by 8.7%

• Decay by 8.7%

Given the following exponential function, identify whether the change represents growth or decay, and determine the percentage rate of increase or decrease.

 $y=96(1.03)^x$  

• Growth by 3%

• Decay by 3%

• Growth by 97%

• Decay by 97%

3400 dollars is placed in an account with an annual interest rate of 8.25%. How much will be in the account after 25 years, to the nearest cent?

• 2.77

• 24670.42

• 1.16

• 36647.08