Question

Cos 3x+5sinx =...??.tolong dgn caranya ya kak

Answer 1

Cos  (2x +x) + 5 sin x = 
= cos 2x cos x - sin 2x sin x + 5 sin x
= (1- 2 sin^2 x) cos x - ( 2sin x cos x sin x) + 5 sin x
= cos x - 2sin^2 x cos x  - 2sin^2 x cos x + 5 sin x
= cos x + 5 sin x - 4  sin^2 x cos x