The graph of f^-1 (x) is
called the inverse function of f (x). The relationship between the two is that the
point (x,y) is on the graph of f (x) if and only if the point (y,x) is on the
graph of f^-1 (x).
This means that if the point
(2, 7) is on f (x), therefore the point (7, 2) is on f^-1 (x).
