मराठी

The Relation 'R' in N × N Such that (A, B) R (C, D) ⇔ a + D = B + C is (A) Reflexive but Not Symmetric (B) Reflexive and Transitive but Not Symmetric (C) an Equivalence Relation (D) None of the These

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प्रश्न

The relation 'R' in N × N such that
(a, b) R (c, d) ⇔ a + d = b + c is ______________ .

पर्याय

  • reflexive but not symmetric

  • reflexive and transitive but not symmetric

  • an equivalence relation

  • none of the these

MCQ
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उत्तर

an equivalence relation

We observe the following properties of relation R.

Reflexivity: Let (a, b) ∈ N × N

⇒ a, b ∈ N

⇒ a+b = b+a

⇒ (a, b) ∈ R

So, R is reflexive on N×N.

Symmetry: Let (a, b), (c, d) ∈ N × N such that (a, b) R (c, d)

⇒ a+d = b+c

⇒ d+a = c +b

⇒ (d, c), (b, a) ∈ R 

So, R is symmetric on N×N.

Transitivity : Let (a, b), (c, d), (e, f) ∈ N×N such that (a, b) R (c, d) and (c, d) R (e, f)

⇒ a+d = b+c and c+f = d+e

⇒ a + d +c + f = b + c + d + e

⇒ a + f = b + e

⇒(a, b) R (e, f)

So, R is transitive on N×N.

Hence, R is an equivalence relation on N.

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पाठ 1: Relations - Exercise 1.4 [पृष्ठ ३१]

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आर.डी. शर्मा Mathematics Volume 1 and 2 [English] Class 12
पाठ 1 Relations
Exercise 1.4 | Q 9 | पृष्ठ ३१

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