Solve Exponential Growth and Decay

What is the a-value (or y-intercept) for the function: f(x) = 800(0.85)^x?

• 800

• 0.85

• 0.15

• x

What is the decay rate for the function: f(x) = 800(0.85)^x?

• 800

• 0.85

• 15%

• x

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation that models this situation?

• y = 8(15,000)^x

• y = 15,000(1.08)^x

• y = 15,000(0.92)^x

• y = 15,000(0.08)^x

The equation f(x) = 300(1.06)^x is being used to calculate the amount of money in a savings account.  What does the 1.06 represent?

• 6% growth

• 6% decay

• 1.06% growth

• .06% decay

Determine if the equation y = 15(1.35)^x represents exponential growth or decay and justify. Hint: Think about the growth and decay equations.

• Growth, because the scale factor is greater than 1

• Growth, because the scale factor is less than 1

• Decay, because the scale factor is greater than 1

• Decay, because the scale factor is less than 1

Write an exponential function to model the situation. Then solve. The value of a car is $18000 and is depreciating at a rate of 12% per year. What will the value of the car be after 10 years?

• V(t) = 18000(.88)^t ; $12986.98

• V(t) = 18000(.12)^t ; $12986.98

• V(t) = 18000(.88)^t ; $5013.02

• V(t) = 18000(.12)^t ; $5013.02

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the decay factor?

• ^0.08

• ^1.08

• 0.92

• 8

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the decay rate?

• ^0.08

• ^1.08

• 0.92

• 8%

Is this exponential growth or decay?

• Growth

• Decay

What is the equation that represents the exponential function in the image below?

• y=3(½)^x

• y=3(2)^x

• y=(2)^x

• y=2(3)^x