Question

1) sin(60°+a)+sin(a-60°)

2)cos(60°+a)+cos(a-60°)

Answer 1

Ответ:

Объяснение:

1)

sin (60 + α) + sin(α - 60) = cos 60 * sin α + sin 60 * cos α  + sin α * cos 60-cos α * sin 60 = √3/2cos α + 1/2sin α + 1/2sin α - √3/2cos α =

= 1/2sin α + 1/2sin α = sin α

2)

cos(60° + α) + cos(α - 60°) = 2cos (60° + α + α - 60°)/2 +cos (60° + α - α + 60°)/2 = 2cosα cos60° = 2cosα * 1/2 = cosα