求证sin(3π/2-a)=-cosa

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/02 20:01:45
求证sin(3π/2-a)=-cosa

求证sin(3π/2-a)=-cosa
求证sin(3π/2-a)=-cosa

求证sin(3π/2-a)=-cosa
sin(3π/2-a)=sin(π+π/2-a)=-sin(π/2-a)=-cosa

sin(3π/2-a)
=sin(3π/2)cosa-cos(3π/2)sina
=-1×cosa-0×sina
=-cosa