Raymond B. answered 03/08/21
Tutor
New to Wyzant
sin^2x + cos^2x = 1
4sinx = -cos^2 + sin^2x + cos^2x = sin^2x
sin^2x -4sinx = 0
sinx(sinx-4) = 0
sinx = 0 (ignore sinx=4 because the sine of any angle is always < 1)
x= 0 or pi