Question

Напишите в виде произведения: sina-sin (a+pi/3)
Помогите пожалуйста с:

Answer 1

sinα-sin(α+π/3)=2sin[(α-α-π/3)/2]·cos[(α+α+π/3)/2]=
=2sin(-π/6)·cos(α+π/6)=-2sin(π/6)·cos(α+π/6)=-2·1/2·cos(α+π/6)=
=-cos(α+π/6)