函数fx=sinx(cosx-(根号3)sinx)
=sinxcosx-√3sin^2x
=1/2sin2x-√3(1-cos2x)/2
=1/2sin2x+√3/2cos2x-√3/2
=sin(2x+π/3)-√3/2
函数的单调递增区间为
2kπ-π/2