1-sinx*cosx=sin2x
1-sin2x/2=sin2x
2-sin2x=2sin2x
2=3sin2x
sin2x=2/3
2x=(-1)^k * arcsin2/3+pn
x=(-1)^k * (arcsin2/3)/2 +pn/2
1-sinx*cosx=sin2x
1-sin2x/2=sin2x
2-sin2x=2sin2x
2=3sin2x
sin2x=2/3
2x=(-1)^k * arcsin2/3+pn
x=(-1)^k * (arcsin2/3)/2 +pn/2