Question

Упростите выражение:
sin(α + 30) cos(α − 30) − cos(α + 30) sin(α − 30)

Answer 1

sin(a+30) cos(a-30)-cos(a+30) sin(a-30)=
sin(a+30)-(a-30))=
sin(a+30-a-30)=
sin(30+30)=
sin60