Algebra Exponential Growth and Decay

Identify each function as representing exponential growth or decay.
f(x) = 4(0.89)^x

• growth

• decay

Is this exponential growth or decay?

• Growth

• Decay

Which is an exponential function?

• y = mx + b

• y - y₁ = m(x - x₁)

• y = ab^x

Write an equation.

• y = (2)2^x

• y = (4)1^x

• y = (1)2^x

Write an equation.

• y = (2)1^x

• y = (1)2^x

• y = (1)0.5^x

Write an equation

• y = (20)0.25^x

• y = (20)0.5^x

• y = (0.5)20^x

Write an equation that presents the population for any year.

• y = x + 5

• y = 5(1)^x

• y = 1.2x + 5

• y = 5(1.2)^x

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

• ^.08

• ^1.08

• .92

• 8

The number of mosquitoes at the beginning of the summer was 4,000. The population of mosquitoes is expected to grow at a rate of 25% a month. How many mosquitoes will there be after 4 months?

• 5000

• 9006

• 9765

• 5433

Using the table below, find the equation that matches

• y = 20(2)^x

• y = 20(1/2)^x

• y = 2(20)^x

• y = 20(1.25)^x