2sin^2x-3sinx-2=0
sinx=t,te[-1,1]
2t^2-3t-2=0
D=9+16=25
t1=(3+5)/4=2/e{-1,1]
t2=-1/2
sinx=-1/2
x=(-1)^(n+1)*pi/6+pi n
2sin^2x-3sinx-2=0
sinx=t,te[-1,1]
2t^2-3t-2=0
D=9+16=25
t1=(3+5)/4=2/e{-1,1]
t2=-1/2
sinx=-1/2
x=(-1)^(n+1)*pi/6+pi n