The xy-plane divides the line joining the points (-1, 3, 4) and, (2, -5, 6)

Let xy-plane divides the line joining the points A(-1, 3, 4) and B(2, -5, 6) in the ratio λ: 1 at point P then point P has coordinates 2λ−1λ+1,−5λ+3λ+1,6λ+4λ+1Point P lies on.xy-plane. so, 6λ+4λ+1=0 or λ=−23Thus, xy plane divides AB externally in the ratio 2 :3.