Jika 3 cos^2 2x+4 cos 2x-4=0 , maka cos x = ….

3cos²2x +4cos2x -4=0
(3cos2x-2)(cos2x+2)=0

*3cos 2x=2
cos2x =2/3
cosx=1/3

*cos2x=-2
cosx= -1

maaf klau slh