JEE Main202331 Jan 2023Morning ShiftMathematicsSets and RelationsActual
Let R be a relation on N × N defined by a , b R c , d if and only if a d b - c = b c a - d . Then R is
Options
- Asymmetric but neither reflexive nor transitive
- Btransitive but neither reflexive nor symmetric
- Creflexive and symmetric but not transitive
- Dsymmetric and transitive but not reflexive
Correct answer
A. symmetric but neither reflexive nor transitive
Step-by-step solution
Given, a , b R c , d ⇒ a d b - c = b c a - d ⇒ a , b R c , d ⇔ b - c b c = a - d a d ⇒ 1 c - 1 b = 1 d - 1 a ⇒ 1 a - 1 b = 1 d - 1 c Reflexive: a , b R a , b ⇒ 1 a - 1 b = 1 b - 1 a It is false. So, given relation is not reflexive. Symmetric: a , b R c , d ⇒ 1 a - 1 b = 1 d - 1 c ⇒ 1 c - 1 d = 1 b - 1 a ∴ c , d R a , b It is symmetric. Transitive: a , b R c , d ⇒ 1 a - 1 b = 1 d - 1 c c , d R e , f = 1 c - 1 d = 1 e - 1 f 1 a - 1 b = 1 e - 1 f ⇒ a ,