Cos 22°-cos38°=sin8°доказать

Question

Cos 22°-cos38°=sin8°
доказать

Answer 1

CosA-cosB = -2*sin((A+B)/2)*sin((A-B)/2)
cos22-cos38 = -2*sin30*sin(-8) = -2*1/2*sin(-8) = sin8