f(x)=(2sinx)×(√3cosx)+(cosx+sinx)×(sinx-cosx)
f(x)=2√3sinxcosx-(cos²x-sin²x)
f(x)=√3sin2x-cos2x
f(x)=2sin(2x-π/6)
函数f(x)的周期是2π/2=π
递增区间是:2kπ-π/2≤2x-π/6≤2kπ+π/2
化简得:kπ-π/6≤x≤kπ+π/3
递增区间是:[kπ-π/6,kπ+π/3],其中k∈Z
当f(x)取得最大值时,2x-π/6=2kπ+π/2,得:x=kπ+π/3
则函数取得最大值时,x的取值集合是:{x|x=kπ+π/3,k∈Z}