Exponential Functions

Which equation is represented by the table?

• y = 40(2)^x

• y = 40(1/2)^x

• y = 40 - 2x

• y = 40 - 1/2x

Which equation is represented by the table?

Which table represents the following equation?

• 
• 
• 
• 

What is the decay rate?

• 80%

• 20%

• 8%

• 2%

Does the equation represent growth or decay?

• Decay

• Growth

Identify the y-intercept (initial value) of the function f(x)=2(4)^x.

• 2
• 4
• (2)^x
• 8

Which of the following is an increasing exponential function whose y-intercept is 50?

• y = 50(.05)^x
• y = 50x - 4
• y = (2)^x + 50
• y = 50(1.4)^x

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

The amount of ibuprofen (medicine for headaches) breaks down by 30% each hour. If a person took a 200 milligram ibuprofen, how much will be left after 3 hours?

• 5.4 mg
• 68.6 mg
• .0054 mg
• 2,400,000 mg

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x