cos73°cos13°+cos17°sin13°=求答案

分类: 作业答案 • 2021-12-18 16:38:04

问题描述：

答

cos73°cos13°+cos17°sin13°=sin17°cos13°+cos17°sin13°=sin(17°+13°)=sin30°=1/2

答

cos73°cos13°+cos17°sin13°
=cos(73°-13°)
=cos60°
=1/2

答

cos73°cos13°+cos17°sin13°
=sin17°cos13°+cos17°sin13°
=sin(17°+13°)
=sin30°
=1/2