Let −−→AB=3^i+^j−^k and −−→AC=^i−^j+3^k. If the point P on the line segment BC is equidistant from AB and AC then −−→AP is
If →r×→b=→c×→b and →r.→a=0 where →a=2^i+3^j−^k,→b=3^i−^j+^k and →c=^i+^j+3^k, then →r is equal to