Inverse function

An Inverse function is a concept of mathematics. A function will calculate some output y, given some input x . This is usually written f(x)=y. The inverse function does the reverse. Let's say g() is the inverse function of f(), then g(y)=x. Or otherwise put, f(g(x))=x.

Not all functions have inverse functions. Finding the inverse of a function can be very difficult to do.