The equation is $\"\"$ and the interval is $\"\"$ .

$\"\"$

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

$\"\"$

$\"\"$ .

If $\"\"$ , then $\"\"$ .

If $\"\"$ , then

$\"\"$

$\"\"$ and $\"\"$

$\"\"$ and $\"\"$ .

Therefore, the solution of $\"\"$ in the interval $\"\"$ is $\"\"$ .

The solution of $\"\"$ in the interval $\"\"$ is $\"\"$ .