Find the distance between P(x₁, y₁) and Q(x₂, y₂) when (i) PQ is parallel to the y-axis (ii) PQ is parallel to the x-axis.

Key points to solve the problem:

• Idea of distance formula- Distance between two points A(x₁,y₁) and B(x₂,y₂) is given by- AB =

Given, P(x₁, y₁) and Q(x₂, y₂) are two points.

i) When PQ is parallel to y-axis

This implies that x – coordinate is constant ⇒ x₂ = x₁

∴ from distance formula:

PQ = = |y₂ - y₁|

ii) When PQ is parallel to x-axis

This implies that y – coordinate is constant ⇒ y₂ = y₁

∴ from distance formula:

PQ = = |x₂ - x₁|

Note: we take modulus because square root gives both positive and negative values but distance is always positive so we make it positive using modulus function.