Exponential Functions What Is the Percentage

Does the graph represent an exponential growth or an exponential decay function?

• Exponential Growth

• Exponential Decay

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.

The amount of downloads for an album on iTunes, g(d), where d is the number of days since the album was first uploaded can be represented as
g(d) = 5^1.5d
How many downloads will the album have after 3 days?

• 125

• 11

• 1398

• 140

Which equation matches the graph?

• y = 2^x+3

• y = 2^x + 3

• y = 2^x

• y = 2^-x

what is the percent increase/decrease of this exponential function? y=47(1.09)^x

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.
What does the value 12 represent?

• The predicted increase in number of elephants in the refuge each year.

• The predicted decrease in number of elephants in the refuge each year.

• The number of years it will take for the elephant population to stop increasing.

• The initial amount of elephants in the park.

The expression 12(1.015)^t models the population of elephants in a wildlife refuge after t years since 1975.
What does the value 1.015 represent?

• The number of elephants was 1,015 in 1975.

• The number of elephants increases by 1.5% each year.

• The number of elephants increases by 101.5% each year.

• The number of elephants is multiplied by 1.015 each year.

Is the following function exponential growth, exponential decay, linear, or none of the above.
g(x) = 740(.001)^3x

• Exponential growth

• Exponential decay

• Linear

• None of the above