Question

Find the ratio in which the line segment joining the points (4,8,10) and (6,10,-8) is divided by the YZ-plane.

• A. internally in the ratio 2:3
• B. externally in the ratio 2:3
• C. internally in the ratio 1:2
• D. externally in the ratio 1:2

Answer 1

The correct option is B

externally in the ratio 2:3

Let the YZ-plane divide the line segment joining the points (4,8,10) and (6,10,-8) in the ratio k:1 at the point P.

The x-coordinate of the point P is given by
$x=\frac{4+6k}{k+1}$
Since P lies on the YZ plane, x=0

$\Rightarrow 4+6k=0\Rightarrow k=\frac{-2}{3}$

Hence, the points are divided by the YZ-plane in the ratio 2:3 externally