Exponential Growth and Decay

A population of 1500 deer decreases by 1.5% per year. At the end of 10 years, there will be approximately 1290 deer in the population. Which function can be used to determine the number of deer, y, in this population at the end of t years?

• y = 1500(1 - 0.015)^t

• y = 1500(0.015)^t

• y = 1500(1 + 0.015)^t

• y = 1500(1.5)^t

There were 417 cell phones sold at an electronics store in January. Since then, cell phone sales at this store have increased at a rate of 3.75% per month. At this rate of growth, which function can be used to determine the monthly cell phone sales x months after January?

• f(x) = 417(3.75)^x

• f(x) = 417(0.0375)^x

• f(x) = 417(1.0375)^x

• f(x) = 417(1.375)^x

An antibiotic is introduced into a colony of 12,000 bacteria during a laboratory experiment. The colony is decreasing by 14.9% per minute. Which function can be used to model the number of bacteria in the colony after x minutes?

• f(x) = 12000(1 + 14.9)^x

• f(x) = 12000(1 - 14.9)^x

• f(x) = 12000(1 + 0.149)^x

• f(x) = 12000(1 - 0.149)^x

A child asks her dad for an allowance that starts with a penny and then doubles every day for a month. Which function can be used to model the amount of money, A, the child will receive each day, x?

• A(x) = 2(0.01)^x

• A(x) = 0.01(2)^x

• A(x) = 0.01(1 - 2)^x

• A(x) = 2(1.01)^x

This is an example of.....

• exponential decay

• exponential growth

• constant change

• a linear function

The population of a school is 2200 and is increasing at a rate of 2% each year. Find the population after 6 years.

Is the pictured graph growth, decay, or linear or none?  

• Exponential Growth

• Exponential Decay

• Linear

• None

Is the pictured graph exponential growth, exponential decay, or linear or none?

• Exponential Growth

• Exponential Decay

• Linear

• None

Is the pictured graph growth, decay, or linear or none?  

• Growth

• Decay

• Linear

• None

Is the pictured graph growth, decay, or linear or none?

• Exponential Growth

• Exponential Decay

• Linear

• None