Exponential Functions

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

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

What is the y-intercept of the function?

• 2
• 3
• 1
• -2

What type of function is y = 7(5/4)^x?

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

Is this exponential growth or decay?

• Growth
• Decay

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

What is the x-intercept of the exponential function? 

• (0,1)
• (0,0)
• There is not one

The amount of ants in a colony, f, that is decaying can be modeled by                      f(x) = 800(.87)^x, where x is the number of days since the decay started. By what percentage is the colony decaying?

• 87%
• 13%
• 800%
• 8.7%

The amount of ants in a colony, f, that is decaying can be modeled by                         f(x) = 800(.87)^x, where x is the number of days since the decay started. Suppose           f(20) = 49. Which of the following is true?

• After 20 days, there are 49 ants in the colony.
• After 49 days there are 20 ants in the colony.
• The amount of ants times 20 is 49.
• After 20 days the amount of ants remaining decreases by 49.

A collectible car has been going up in price by 10% each year. If the car is already worth $29,000, how much will the car be worth in 5 years?

• $0.29
• $2,900,000,000
• $46,704.79
• $145,000

The expression 12(1.015)^t models the population of elephants in a wildlife refuge after t years since 1975.
Is the population of elephants increasing or decreasing?

• Increasing
• Decreasing