Exponential Function Interpretation

A student used  $f\left(x\right)=500\left(1.012\right)^x$  to show how the balance in a savings account will increase over time. What does the 500 represent?

• The interest the account earned for the first year

• The annual interest rate of the savings account

• The number of years the savings account has earned interest

• The starting balance of the savings account

What is the value of the y-intercept of the graph of  $h\left(x\right)=13\left(2.4\right)^x$  ?

• 2.4

• 40%

• 15.4

• 13

The rule $f\left(x\right)=200\left(\frac{1}{2}\right)^x$  represents the the number of bugs after a heavy rain after x hours. What does   $f\left(3\right)=25$  mean?

• After 25 minutes, there are 3 bugs.

• After 3 hours, there are 25 bugs. 

• After 3 minutes, there are 25 bugs.

• After 25 hours, there are 3 bugs. 

Scientists are studying bacteria very carefully. The function  $f\left(x\right)=10000\left(1.05\right)^x$  gives the number of bacteria at the end of x weeks. Which of the following statements is the best description of  $f\left(2\right)=11025$ ? 

• There are 11025 bacteria after 2 days. 

• There are 2 bacteria after 11025 days. 

• There are 11025 bacteria after 2 weeks.

• There are 2 bacteria after 11025 weeks.

A bank account earning annual compound interest was opened, and no additional withdrawals or deposits were made after the initial deposit. The balance in the account after x years can be modeled by  $b\left(x\right)=850\left(1.025\right)^x$  . Which statement is the best interpretation of one of the values in this function?

• The initial balance in the account decreases at a rate of 97.5% each year.

• The balance in the account increases at a rate of 25% each year.

• The initial balance in the account was $850.

• The balance in the account at the end of 1 year is $850.

Which statement about the graph of  $y=12(0.4)^x$  is true?

• The coordinates of the x-intercept are  $\left(0.4,0\right)$  

• The equation of the asymptote is  $x=0$  

• The graph includes the point  $\left(4,0\right)$  

• The coordinates of the y-intercept are  $\left(0,12\right)$  

What is a, the starting term, for the function: f(x) = 300(1.16)^x?

• 300

• 1.16

• .16

• x

Given y=3^x determine the y-intercept 

• (0,1)

• (0,3)

• No Y-intercept

• y=1