计算值 COS(-2040°)
问题描述:
计算值 COS(-2040°)
答
=cos(-60°)
=cos60°
=1/2
答
COS(-2040°)
=cos(2160-2040)
=cos120
=-cos60
=-0.5
答
=cos2040
-=cos(360×5+240)
=cos240
=cos(180+60)
=-cos60
=-1/2