solve the multiple-angle equation.

Question

Equation : .

Answer 1

The equation is .

Let , the function has a period of , first find all solutions in the interval .

The function is negative in third and fourth quadrant.

So the solutions are ; and substitute in .

Finally, add multiples of to each of these solutions to get the general form

where n is integer.

Divide each side by 2.

The solutions are .