要得到y=cos(3x-π/4)的图像,且使平移距离最短,则需将y=sin3x的图像?

问题描述:

要得到y=cos(3x-π/4)的图像,且使平移距离最短,则需将y=sin3x的图像?
过程

y=cos(3x-π/4)
=cos(π/4-3x)
=sin[π/2-(π/4-3x)]
=sin(3x+π/4)
=sin[3(x+π/12)]
所以应该是向右平移π/12