Given the points P(-2,5,9) and Q(3,-2,4)

Let the plane YZ-plane divide line segment PQ at point G(0,y,z) in the ratio m:n.

The coordinates of the point G which divides the line joining points A(x₁,y₁,z₁) and B(x₂,y₂,z₂) in the ratio m:n is given by

Here, we have m:n

x₁ = -2 y₁ = 5 z₁ = 9

x₂ = 3 y₂ = -2 z₂ = 4

By using the above formula, we get,

Now, this is the same point as G(0,y,z),

As the x-coordinate is zero,

[Cross Multiplying]

3m – 2n = 0 × (m + n)

3m – 2n = 0

3m = 2n

Therefore, the ratio in which the plane-YZ divides the line joining A & B is 2:3