cos225°+tan240°+sin420°
问题描述：
cos225°+tan240°+sin420°
我没分了请见谅,明天要交呀!
答
cos225°+tan240°+sin420°
=cos(180°+45°)+tan(180°+60°)+sin(360°+60°)
=-cos45°+tan60°+sin+60°
=-√2/2+√3+√3/2
=-√2/2+3√3/2