Tolong no.9 yahhh...

Sin2x = 2sinx cosx sin 2x -sinx= sinx(2cosx-1)=0 untuk sin x =0 atau cos x = 1/2 maka X=0;180;.360 untu cos x = 1/2 X = 60;210

Cos 2x + cos x = 02cos²x-1 + cosx = 0
2cos²x + cosx - 1 = 0
(2cosx-1) (cosx+1) = 0
* 2cosx-1 = 02cos x = 1cosx = 1/2cosx = cos 60 atau x= -60+k.360x = 60+k.360
k=1 --> x = 300k=0 --> x=60
* cosx+1 = 0cosx = -1cosx = c0s 180x = 180+k.360 atau x =-180+k.360k=0 --> x=180 k=1 --> x=180Hp = {60,180,300}