Question

怎样把根据y=Asin(wx+φ)的图象变换成y=Acos(wx+φ)

Answer 1

y=Asin(wx+a)变到y=Asin(x+a),再平移变到y=Asin(x),上下压缩变到y=sin(x)

再平移pi/2得到y=cos(x),上下压缩变到y=Bcos(x),再平移变到y=Bcos(x+b),最后水平拉伸变到y=Bcos(kx+b)