f（x）=2又根号3sin（wx／2）cos（wx／2）-2sin^2wx／2
=根号3sinwx+(1-2sin^2wx／2)-1
=根号3sinwx+coswx-1
=2(sinwx*cosπ/6+coswx*sinπ/6)-1
=2sin(wx+π/6)-1