若sin(α-π/3),则cos﹙α+π/6﹚=
问题描述:
若sin(α-π/3),则cos﹙α+π/6﹚=
答
sin(α-π/3)=-sin(π/2-(π/6+α))=-cos(α+π/6)sin(α-π/3)=3/5结果应该是-3/5
若sin(α-π/3),则cos﹙α+π/6﹚=
sin(α-π/3)=-sin(π/2-(π/6+α))=-cos(α+π/6)sin(α-π/3)=3/5结果应该是-3/5