The equation is .

Squaring on both sides.

From the trignometric identity .

The solution set for the above equation in :

and .

Check each solution in the original equation.

Check for :

Check for :

Check for :

Check for :

Therefore, the only solutions to this equation is on the interval  are and .

Graph the functions and on the same graph on the interval .

(1). Draw the coordinate plane.

(2).Graph the functions and .

Graph :

Observe the graph :  

The graphs intersects at and .  

So the solutions are and .

The solutions for the interval are and .