The function is .
Find when
is the inverse of the function
.
Theorem 7 :
\If is a one to one differentiable function with inverse function
and
then the inverse function is differentiable at
and
.
Find .
.
Substitute in the function.
Therefore then
.
Apply derivative on each side with respect to .
.
Substitute then
.
is the inverse function of
then
.
.
.