Exponential Functions Review

Write an equation that models the following situation:
Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1.14)^x

• y=6(0.86)^x

Which equation is represented by the table?

• y = 40(2)^x

• y = 40(1/2)^x

• y = 40 - 2x

• y = 40 - 1/2x

What is the percent growth of the situation represented by f(x)=10(1.3)^x?

• 30

• 0.3

• 7

• 70

Identify the y-intercept in the function f(x)=13(.27)^x

• (.27)^x

• .27

• 13

• 3.51

• x > 4

• y > 4

• all reall numbers

• y > 0

• x = 4

• y = 4

• all reall numbers

• y = 0

• 9600

• 12,800

• 200

• 8000

An adult takes 800 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How much ibuprofen is left after 6 hours? (hint: create equation first)

• 101

• 102

• 103

• 104

• 1600

• 2

• There is not enough information to tell.

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