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Given a non-empty set X, consider P (X), which is the set of all subsets of X. Define the relation R in P(X) as follows: For subsets A, B in P(X), ARB if and only if - Mathematics

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प्रश्न

Given a non-empty set X, consider P (X), which is the set of all subsets of X. Define the relation R in P(X) as follows:

For subsets A, B in P(X), ARB if and only if A ⊂ B. Is R an equivalence relation on P(X)? Justify your answer.

योग

उत्तर

(i) reflexive

Since every set is a subset of itself, ARA for all A ∈ P(X).

∴R is reflexive.

(ii) symmetric

Let ARB ⇒ A ⊂ B.

This cannot be implied to B ⊂ A.

For instance, if A = {1, 2} and B = {1, 2, 3}, then it cannot be implied that B is related to A.

= ARB ≠ BRA

∴ R is not symmetric.

(iii) transitive

Further, if ARB and BRC, then A ⊂ B and B ⊂ C.

⇒ A ⊂ C

⇒ ARC

∴ R is transitive.

Hence, R is not an equivalence relation to P(X).

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अध्याय 1: Relations and Functions - Exercise 1.5 [पृष्ठ २९]

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एनसीईआरटी Mathematics [English] Class 12
अध्याय 1 Relations and Functions
Exercise 1.5 | Q 8 | पृष्ठ २९

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