sin^2(x) +2sin x cos x +cos^2(x) =1
1+2sinxcos x =1
2sinxcosx=0
sin x = 0 cos x = 0
x = pin x = pin/2
sin^2(x) +2sin x cos x +cos^2(x) =1
1+2sinxcos x =1
2sinxcosx=0
sin x = 0 cos x = 0
x = pin x = pin/2