Question

The number of caps a new online store sells increases by a factor of 4 each month. The function f(x) = 4x represents the number of caps sold in month x. When does the store sell 64 caps?

Answer 1

Given

... f(x) = 4^x

Find

... x for f(x) = 64

Solution

Rewrite 64 as a power of 4, then equate exponents.

... 64 = 4^x

... 4^3 = 4^x

... 3 = x

The store sells 64 caps in month 3.