sinx的单调增区间为[-π/2+2kπ，π/2+2kπ]根据左加右减，sin(x-π/3)的图像就是将sinx的图像向右平移π/3个单位将sinx的单调增区间[-π/2+2kπ，π/2+2kπ]右移π/3个单位得sin(x-π/3)的单调增区间[-π/6+2kπ，5π/6+2kπ]
