The integral is
.
Rewrite the integral as
.
.
Consider
.
Apply derivative on each side with respect to
.

.
Substitute
and
in
.



.
Consider the integral
.
Substitute
.
Apply derivative on each side with respect to
.

.
Substitute
and
in
.



Apply double angle formula :
.


Substitute
and
and
.
.
Substitute the value in 
.
.