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
.
.
.