The function is and
.
Find .
Theorem 7:
\If is a one to one differentiable function with inverse function
and
then the inverse function is
differentiable at and
.
Find .
Equate the function to .
.
is clearly one root of the equation.
Therefore then
.
.
Differentiate the function with respect to .
.
Power rule of derivatives : .
.
.
.