Question

Find the ratio in which the line segment joining the points (2, 4, 5) and (3, −5, 4) is divided by the YZ −plane.

Answer 1

Let the required ratio be m: n since, the point lies in YZ plane, so its x-coordinate is 0.

\(\frac{mx_2+nx_1}{m+n}=0\\=\frac{m.3+n.2}{m+n}\\=3m=-2n\\=m:n=-2:3\)

The ratio is 2 ∶ 3 and the division is external.