求证(tanxtan2x/tan2x-tanx)/(tan2x-tanx)+√3(sin^2x-cos^2x)=2sin(2x-π/3)

问题描述:

求证(tanxtan2x/tan2x-tanx)/(tan2x-tanx)+√3(sin^2x-cos^2x)=2sin(2x-π/3)

tanxtan2x/(tan2x-tanx)=sinxsin2x/(sin2xcosx-sinxcos2x)=sinxsin2x/sin(2x-x)=sin2x(tanxtan2x/(tan2x-tanx))+√3[(sinx)^2-(cosx)^2]=sin2x-√3cos2x=2sin(2x-π/3)