Determine specific solutions if any to the equation on the i

Determine specific solutions (if any) to the equation on the interval [0,pi).

cos 2 theta -4 = -7 sin theta

cos2 - 4 = -7sin

1 - 2 sin^{^2}() - 4 = -7sin

2 sin^{^2}() - 7sin + 3 = 0

Let sin = x, then

2x^2 - 7x + 3 = 0

x = 3, 0.5 = sin

sin = 0.5 [sin = 3 is not possible]

= 30 degree