2 sin^2x+3cos^2x+2sinx=0
cos^2x=1-sin^2x
sinx=t
2t^2+3-3t^2+2t=0
-t^2+2t+3=0
t^2-2t-3=0
D=4-4*1*-3=16
t=2+4/2=3
t2=2-4/2=-1
sinx=3
sinx=-1
x=-pi/2+2pi*k
x=-1arcsin(3)+2pi*l
