Question

40 Балов!
sin x = tg^2 (x/2) * (1+cos x)

Answer 1

sinx=tg²x/2*+1+cosx)

sinx=(1-cosx)/(1+cosx)*(1+cosx)
sinx=1-cosx ;cosx≠-1
sinx+cosx=1
(sinx+cosx)²=1
sin²x+2sinxcosx+cos²x=1

2sinxcosx=0
sinx=0;x=πn
cosx=0;x=π/2+πn;n€z


(tg²a=(1-cos2a)/(1+cos2x))