$\"\"$

\

The trigonometric expression is $\"\"$ .

\

$\"\"$ .

\

Apply tigonometric reciprocal identity: $\"\"$ .

\

$\"\"$ .

\

$\"\"$ is in fourth quadrant, $\"\"$ .

\

Apply half-angle formula: $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

Substitute $\"\"$ .

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$

\

$\"\"$ .

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .