y=sin(pai/3-2x)的单调减区间
问题描述：
y=sin(pai/3-2x)的单调减区间
答
y=-sin(2x-π/3)
令t = 2x-π/3
y= -sint
易得：
-π/2+2kπ ≤ 2x-π/3 ≤π/2+2kπ
-12/π+kπ ≤ x ≤ 5π/6+kπ