sin67.5度cos22.5度+sin225度cos67.5度=

分类: 作业答案 • 2022-06-02 23:12:37

问题描述：

答

sin67.5度cos22.5度+sin22.5度cos67.5度
=sin67.5°cos22.5°-cos67.5°sin22.5°
=sin(67.5°-22.5°)
=sin45°
=√2/2