$\"\"$

The trigonometric equation is $\"\"$ .

Rewrite the expression as $\"\"$ .

This type of trigonometric equation cannot be solved directly.

Solutions of such trigonometric equations can be found graphically.

Graph :

Graph the function $\"\"$ and $\"\"$ .

$\"\"$

Observe the graph :

The graph of the function $\"\"$ touches the line $\"\"$ at $\"\"$ and $\"\"$ .

Solution of the equation are $\"\"$ and $\"\"$ .

$\"\"$

Solution of the equation are $\"\"$ and $\"\"$ .