Exponential Functions Mixed Practice

In an exponential function, what does the 'a' represent? 

• SLOPE
• RATE OF CHANGE
• Y-INTERCEPT
• COMMON RATIO

What is the y-intercept of the function?

• 2
• 3
• 1
• -2

Identify the y-intercept (initial value) of the function f(x)=2(4)^x.

• 2
• 4
• (2)^x
• 8

True or False: This is an exponential function.

• True

• False

Which function models this table?

• $f\left(x\right)=2\cdot4^x$

• $f\left(x\right)=4^x$

• $f\left(x\right)=4\cdot2^x$

• $f\left(x\right)=8^x$

Which of the following is an increasing exponential function whose y-intercept is 50?

• y = 50(.05)^x
• y = 50x - 4
• y = (2)^x + 50
• y = 50(1.4)^x

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