在三角形ABC中,AB=根号三,AC=2,若O为△ABC内部一点,且 向量OA+OB+OC=0向量,则向量AO*BC=?

BC = (BA+AC)AO。BC = AO。(BA+AC)= (OB+OC)。(BA+AC) ( AO=OB+OC)=( OA+AB+OA+AC)(BA+AC)= 2OA。(BA+AC) + |AC|² -|AB|²= 2OA。BC + 4-3- OA。BC = 2OA。BC + 13OA。BC = -1OA。BC = -1/3