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

Solution:

The given points are P (x₁, y₁) and Q (x₂, y₂)

(i) When PQ is parallel to the y-axis, x₁ = x₂.

In this case, distance between P and Q = √(x₂ - x₁)² + (y₂ - y₁)²

PQ = √(y₂ - y₁)²

= |y₂ - y₁|

(ii) When PQ is parallel to the x-axis y₁ = y₂

In this case, distance between P and Q = √(x₂ - x₁)² + (y₂ - y₁)²

PQ = √(x₂ - x₁)²

= |x₂ - x₁|

NCERT Solutions Class 11 Maths Chapter 10 Exercise 10.1 Question 3

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

Summary:

We found out that the distance between P (x₁, y₁) and Q (x₂, y₂) when PQ is parallel to y-axis is |y₂ - y₁| and when PQ is parallel to the x-axis is |x₂ - x₁|.