sina(丌/6+2k丌).cos(11/3丌)-tan(5/4丌+2k丌)
问题描述：
sina(丌/6+2k丌).cos(11/3丌)-tan(5/4丌+2k丌)
化简并计算
答
=sin(丌/6)*cos(丌/3)-tan(丌/4)
=(1/2)*(1/2)-1
=-3/4