Cos2x+cos14x+cos6x+cos10x преобразовать в произведение

Question

Cos2x+cos14x+cos6x+cos10x преобразовать в произведение

Answer 1

Cos2x+cos14x+cos6x+cos10x =
= 2cos8xcos6x+2cos8xcos2x =
= 2cos8x(cos6x+cos2x) = 4cos8xcos4xcos2x