Exponential Functions (Word Problems)

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

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

• y=8(15,000)^x
• y=15,000(1.08)^x
• y=15,000(0.92)^x
• y=15,000(0.08)^x

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x
• y=30(5000)^x
• y=5000(1.3)^x
• y=5000x^x

A particular type of cell triples in number every hour. Which function can be used to find the number of cells present at the end of h hours if there are initially 6 of these cells?

• f(h) = 3(6)^h

• f(h) = 6x^h

• f(h) = 6(3)^h

• f(h) = 3(6h)

What type of function does the equation y = 2^xrepresent?

• Exponential Decay

• Linear

• Exponential Decay

• Exponential Growth

What type of function does the equation f(x) = 200(0.79)^x represent?

• Exponential Growth

• Exponential Decay

• Linear

• Quadratic