Jawabanmu

2014-06-09T15:47:24+07:00
1/2akar3 . 1/2 - 1/2akar3
= 1/4akar3 -1/2akar3
1 3 1
2014-06-09T16:00:05+07:00
Cos 30° = 1/2√3
cos 60° = 1/2
sin  60° = 1/2√3

= cos 30° . cos 60° - sin 60°
= 1/2√3    . 1/2       - 1/2√3
= 1/4√3                  -  1/2√3
= 1/4√3 - 1/2√3
1 3 1