$\"\"$

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

Related function is $\"\"$ .

Draw a coordinate plane.

Graph the function $\"\"$ .

Graph : \ \

$\"\"$

Observe the graph of the function : \ \

The graph of the function touches the x - axis at $\"\"$ .

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

$\"\"$

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