Let f(x) = sin2x and g(x) = sin(0.5x).

Consider the equation f(x) = g(x).

Find the number of solutions to this equation, for 0 less than or equal toxless than or equal to 3pi/2.

I know there are four solutions from graphing by hand and that I can determine the solutions using a graphing calculator. BUT how do I determine the solutions by hand?