Question

find 3Sin^2x-2Cos^2x-Sinx=0

Answer 1

sin^2 + cos^2 = 1 ----> cos^2 = 1 - sin^2
\[3 \sin^2 x -2(1-\sin^2 x) -\sin x = 0\]
\[5 \sin^2 x - \sin x - 2 = 0\]

solve it like a quadratic
u = sin x
\[5u^2 - u -2 = 0\]

Answer 2

Tyvm