$\"\"$

\

The trigonometric identity is $\"\"$ .

\

Consider $\"\"$ .

\

Apply pythagorean identity: $\"\"$

\

Substitute $\"\"$ in the above equation.

\

$\"\"$ \ \

\

$\"\"$

\

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

\

$\"\"$

\

$\"\"$ .

\

$\"\"$

\

$\"\"$ .