The function is .
The function is continuous in the interval .
Derivative of is
, which is negative in the interval
.
So the function is one-to-one and is strictly monotonic.
\Therefore, inverse exists.
\From theorem 5.9 : .
Equate to
.
By trial and error process we will get .
Thus,
.
.
Substitute in above expression.
.
Consider .
Substitute in
.
.
.