$\"\"$

The trigonometric equation is $\"\"$ .

Apply reciprocal identity : $\"\"$ .

Apply quotient identity : $\"\"$ . \ \

$\"\"$

The general solution of $\"\"$ is $\"\"$ , where $\"image\"$ is an integer.

The solutions is $\"\"$ , where $\"image\"$ is an integer.

$\"\"$

The solutions is $\"\"$ , where $\"image\"$ is an integer.