Question

Given the function f(x)=3^x, find the value of f^-1(27)

Answer 1

This is asking you to solve the equation ...

... 27 = 3^x

You can use logarithms to find

... log(27) = x·log(3)

... log(27)/log(3) = x = 1.43136376.../0.47712125...

... x = 3

Or, you can use your knowledge of small cubes and match exponents.

... 3^3 = 3^x

... 3 = x