




If g[f(x)] = x for x in some region R, then g is called the inverse of f and is defined on f(R).
We usually denote such g(x) as f ^{1}(x).
The graph of g is obtained by reflecting the graph of f with respect to the line y = x.
Notice that the derivative of f ^{1} is the reciprocal of that of f, at corresponding points.