$\"\"$

The equation is $\"\"$ .

$\"\"$

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

Therefore, the general solution of $\"\"$ is $\"\"$ , where $\"\"$ is an integer.

$\"\"$

Since $\"\"$ is positive in first and second quadrant, the second solution is $\"\"$

$\"\"$

Therefore, the general solution of $\"\"$ is $\"\"$ , where $\"\"$ is an integer.

$\"\"$

The solutions are $\"\"$ and $\"\"$ , where $\"\"$ is an integer.