y=3sin(2x-π/6)
=3sin(2x+π/2-2π/3)
=3cos(2x-2π/3)
=3cos[2(x-π/3)]
只需把函数y=3cos2x向右平移π/3个单位得到
y=3cos[2(x-π/3)]即y=3sin(2x-π/6)图像