P0,4,−1,Q−1,2,−3 and R5,0,−6 are the vertices of a triangle. The direction ratios of the internal angular bisector of∠PQR are

Given P0,4,-1, Q-1,2,-3 and R5,0,-6.Now QP→=1,2,2 and QR→=6,-2-3.The angle bisector of ∠PQR is ±QP→QP→+QR→QR→=±2521,821,521⇒25,8,5 are d.r's of the angular bisector of ∠PQR