为什么cos^2[π/2-(π/4+x)]=cos^2(π/4-x)呢怎么变的呢?我怎么都没做通都没变过来,看不懂哇

Question

为什么cos^2[π/2-(π/4+x)]=cos^2(π/4-x)呢
怎么变的呢?我怎么都没做通 都没变过来,看不懂哇

Answer 1

[π/2-(π/4+x)]=(π/2-π/4-x)=(π/4-x)