3-2cos^{2}x -3sinx=0
3-2(1-sin^{2}x)-3sinx=0
2sin^{2}x -3sinx +1=0
sinx=1, \frac{1}{2}
\therefore x=90^{\circ},270^{\circ},30^{\circ}, 150^{\circ}
eqn: 2sin^{2}x +cosx -2 =0
2(1-cos^{2}x) +cosx-2=0
-2cos^{2}x +cosx =0
cosx=-0.5, 0.5
\therefore x=60^{\circ}, 120^{\circ}, 240^{\circ}, 300^{\circ}