A *function* (f) takes in some *input* (x) and transforms it into an *output* (f(x)). An *inverse function* (f^-1) goes the other way around. You can feed it in an *output* of f and get back the original input (f^-1(f(x)) = x). In practice, we find this inverse function by solving for the input of the original function. See the picture for the work!