sin120도=sin60=루트3/2.sin120도=sin(60도+60도)=sin60cos60+cos60sin60=루트3/2x1/2+1/2x루트3/2이죠.루트3/4+루트3/4=2루트3/4=루트3/2 따라서sin120도=sin60
당신은 어느 그룹입니까?