The integral is
. 
Consider
.
The function is
.
Substitute
.


.
The integrand
is an odd function.
If
is an odd function, then
.
.
Consider
.
Rewrite the expression as
.
The function is
.
Substitute
.


.
The integrand
is an even function.
If
is an even function, then
.

.
.
Consider
.
Rewrite the expression as
.
Consider
.
The function is
.
Substitute
.
.
The integrand
is an odd function.
If
is an odd function, then
.
.
Consider
.
The function is
.
Substitute
.
.
The integrand
is an even function.
If
is an even function, then
. 

.
Substitute
,
,
and
in integral.

.
.