$\"\"$

\

The expression is $\"\"$ .

\

Rewrite the expression.

\

$\"\"$ .

\

$\"\"$ .

\

Using the half angle trigonometric identity: $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .