Question

Cell phone usage grew about 23% each year from 2010 to
2016. If cell phone usage in 2010 was 43 million, write a function to model U.S. cell
phone usage over that time period.

Answer 1

The exponential function that models U.S. cellphone usage over that time period, in millions, is:

$A(t) = 43(1.23)^t, 0 \leq t \leq 6$

What is an exponential function?

An increasing exponential function is modeled by:

$A(t) = A(0)(1 + r)^t$

In which:

• A(0) is the initial value.

• r is the growth rate, as a decimal.

In this problem:

• The usage grew 23% in the time period, hence r = 0.23.

• The initial usage was of A(0) = 43.

Then, considering the function is valid between 2010(t = 0) and 2016(t = 6), it is given by:

$A(t) = 43(1.23)^t, 0 \leq t \leq 6$

More can be learned about exponential functions at https://brainly.com/question/25537936