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Determine whether the following relation is reflexive, symmetric and transitive: Relation R in the set A = {1, 2, 3, ..., 13, 14} defined as R = {(x, y) : 3x – y = 0}.

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Question

Determine whether the following relation is reflexive, symmetric and transitive:

Relation R in the set A = {1, 2, 3, ..., 13, 14} defined as R = {(x, y) : 3x – y = 0}.

Sum
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Solution

A = {1, 2, 3, ..., 13, 14}

R = {(x, y) : 3x – y = 0}

∴ R = {(1, 3), (2, 6), (3, 9), (4, 12)}

R is not reflexive since (1, 1), (2, 2), ..., (14, 14) ∉ R.

Also, R is not symmetric, as (1, 3) ∈ R, but (3, 1) ∉ R [3(3) – 1 ≠ 0].

Also, R is not transitive, as (1, 3), (3, 9) ∈ R, but (1, 9) ∉ R [3(1) – 9 ≠ 0].

Hence, R is neither reflexive, nor symmetric, nor transitive.

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Chapter 1: Relations and Functions - EXERCISE 1.1 [Page 5]

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NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 1 Relations and Functions
EXERCISE 1.1 | Q 1. (i) | Page 5

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