The correct option is D 1
tanx+tan[x+π3]+tan[x+2π3]=3
tanx+tanx+√31−√3tanx+tanx−√31+√3tanx=3=3
⇒tan(1−3tan2x)+(tanx+√3)(1+√3tanx)+(tanx−√3)(1−√3tanx)1−3tan2x=3
⇒[tanx−3tan3x+tanx+√3tan2x+√3+3tanx+tanx−√3tan2x−√3+3tanx]1−3tan2x=3
⇒9tanx−3tan3x1−3tan2x=3
⇒3tanx−tan3x1−3tan2x=1
⇒tan3x=1