Exponential Functions

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

• Exponential Growth
• Exponential Decay

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.

Is the graph exponential growth or decay?

• Exponential growth
• Exponential decay

Pick the equation that is exponential growth

• y=2(0.5)^x
• y = 0.5(2)^x

The amount of cola in a soda machine decreases by a rate of 5% each hour. The amount of cola in the machine was originally 75 gallons.

Which function models the amount of cola in gallons after h hours?

• f(h) = 75(-5)^h

• f(h) = -5(75)^h

• f(h) = .95(75)^h

• f(h) = 75(.95)^h

Write an exponential function to model the situation. You invest $1500. Your investment increases at a rate of 3.5%.

• B(t) = 1500(0.965)^t

• B(t) = 1500(1.035)^t

• B(t) = 1500(.035)^t

• B(t) = 1500(1.965)^t

Write an exponential function to model the situation. The value of a car is $18000 and is depreciating at a rate of 12% per year.

• V(t) = .88(18000)^t

• V(t) = .12(18000)^t

• V(t) = 18000(.88)^t

• V(t) = 18000(.12)^t

Which equation describes the story below?

You start with $5 and triple your money every day.

• y=5(3)^x

• y=5^x

• y=5(3x)

• y=15^x

A tennis tournament begins with 128 players. At the end of round one, there will be 64 players. There are 32 players at the end of round 2 and 16 players remaining after round 3. Write the equation that best models this situation.

• y = -64x + 128

• y = 0.5x + 128

• y = 128(0.5)^x

• y = 128(2)^x

The population of 10,000 mosquitos is cut in half each month when a colony of bats moves in the area. What is the equation?