f(x)=-根号3sin^2x+sinxcosx
=-√3/2(1-cos2x)+1/2sin2x
=√3/2cos2x+1/2sin2x-√3/2
=sin(2x+π/3)-√3/2
(1)f((23π)/6)=-√3/2
(2)因为x属于（0,π）所以
π/3