Question

Помогите Плизз Решить.
cos 2x +cos 4x = 2cos 3x

Answer 1

cos2x+cos4x=2cos3x
2cos3xcosx-2cos3x=0
2cos3x(cosx+1)=0
cos3x=0
3x=п/2+пn,n€z
x=п/6+пn/3,n€z
cosx=-1
x=п+2пn,n€z