$\"\"$

\

The integral is $\"\"$ .

\

$\"\"$

\

Trignometric identity : $\"\"$ .

\

$\"\"$

\

Subustiute $\"\"$ and $\"\"$ .

\

$\"\"$

\

Subustiute $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$ $\"\"$ .