Special Exponential Functions

A population of mutant venus fly trap plants are taking over an island in the South Pacific, capturing everything from insects to small rodents. When they were first discovered they covered 4 square kilometers. As the population grows, the plants spread and cover more land. How many years will it take for the plants to occupy 400 km²?

• 8 years

• 9 years

• 10 years

• 11 years

This graph models y = (0.2)^x - 3. Which statement describes what happens to the y value as x increases?

• As the value of x becomes very large, the value of y approaches - 0.2.

• As the value of x becomes very large, the value of y approaches -3.

• As the value of x becomes very large, the value of y approaches -2.

• As the value of x becomes very large, the value of y will gradually

  decrease to negative infinity.

The diagram shows the function f(x) = 3^x + 2. How could you name an ordered pair of this function.

• Option 1: Plug the function into the calculator and look at the table.

• Option 2: Randomly write down your favorite numbers.

• Option 3: Plug in zero for x, which gives an y output of 3 (1+2) for the point (0, 3)

• Option 1 and 3

• None of the above

Which equation matches the graph?

• y = 2^x+3

• y = 2^x + 3

• y = 2^x

• y = 2^-x

• 800

• 0.95

• 2000

• decay

• growth

• 5%

• 95%

Create the exponential function with the following attributes:

Asymptote: y = 0

Initial value: 3

Point on the graph: (2, 6)

Growth

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?

A shipping company started with 40 employees. The number of employees at the shipping company increases at a rate of 7.5% each year. Which function can be used to model the number of employees, f(x), at the shipping company after x years?

A shipping company started with 40 employees. The number of employees in the shipping company increases at a rate of 7.5% each year. What function can be used to model the number of employees, f(x), in the shipping company after x years?

Solve for x:

• 1

• 2

• .5

• 4