Question

A city's population increases by 5% every year. If its population today is 300,000, write a function that models the population after x years.

Answer 1

f(x) = 300,000(1.05)^x

Explanation:

Use the exponential growth equation:

f(x) = a(1 + r)^x

Plug in 300,000 as a, since it is the original population:

f(x) = 300,000(1 + r)^x

The city's population is growing at 5% each year, so plug in 0.05 as r:

f(x) = 300,000(1 + 0.05)^x

f(x) = 300,000(1.05)^x

So, the function for the population growth is f(x) = 300,000(1.05)^x