已知sin(α-π⼀4)=1⼀3,则cos(π⼀4+α)的值等于

2025-05-02 14:22:32
推荐回答(1个)
回答1:

cos(π/4+α)
=cos(π/2+α-π/4)
=-sin(α-π/4)
=-1/3