y=√3cosx+sinx
=2sin(x+π/3)
所以y=√3cosx+sinx的单减区间为
2kπ+π/2≤x+π/3≤2kπ+3π/2(k∈Z)
即
2kπ+π/6≤x≤2kπ+7π/6 (k∈Z)