The function is
.

.
Hence the function is an odd function.
\Integral of symmetric functions :
\Suppose
is continuous on
,
If
is even function i.e
, then
.
If
is odd function i.e
, then
.
Therefore, from the integral of symmetric functions definition,
\
.
Consider the fact
for all
.
Comparision property of definite integrals :
\If
for
, then
.
Here
and
.

\
Add
on each side.

.
Hence it is verified.
\
.