Question

упростить выражение
sin(a+b)+sin(a-b);
cos($cos( pi - alpha )+cos3/2 pi + alpha$
1+2cos(-α)sin(-α)

Answer 1

sin (α+β)+sin (α-β) = sinα*cosβ+sinβ*cosα + sinα*cosβ-sinβ*cosα=2sinα*cosβ

cos (cos(π-α)+cos(3π/2 + α) = cos(-cosα+cosα)=0

1+2cos(-α)*sin(-α)=1+2cosα*(-sinα)=1-2cosα*sinα=1-sin2α