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Give an example of a relation which is reflexive and symmetric but not transitive?

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प्रश्न

Give an example of a relation which is reflexive and symmetric but not transitive?

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उत्तर

Let A = {4, 6, 8}

Let the relation R defined on a set A be as follows:

R = {(4, 4), (6, 6), (8, 8), (4, 6), (6, 4), (6, 8), (8, 6)}

⇒ The relation R is reflexive because for every element a ∈ A, (a, a) ∈ R, i.e., (4, 4), (6, 6), (8, 8) ∈ R.

∴ R is Reflexive.

⇒ The relation R is symmetric, because (a, b) ∈ R and (b, a) ∈ R, for all a, b ∈ R.

∴ R is symmetric.

⇒ The relation R is not transitive, because (4, 6), (6, 8) ∈ R, but (4, 8) ∉ R.

∴ R is not transitive.

Thus, R is reflexive and symmetric but not transitive.

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अध्याय 1: Relations - Exercise 1.1 [पृष्ठ ११]

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आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
अध्याय 1 Relations
Exercise 1.1 | Q 14.1 | पृष्ठ ११

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