Jawabanmu

2014-06-05T20:28:18+07:00
2cos 2x = akar 3
cos 2x = akar3/2
cos 2x = 1/2 akar 3
cos 2x = cos 30
2x = 30
x = 15

x satu = a + k.360
= 15 + 0.360
=15

x dua = -a + k.360
= -15 + 1.360
=345
hp : {15 ; 345}