Example 5 - Chapter 1 Class 12 Relation and Functions
Last updated at April 16, 2024 by Teachoo
To prove relation reflexive, transitive, symmetric and equivalent
What is reflexive, symmetric, transitive relation?
You are here
You are here
Chapter 1 Class 12 Relation and Functions
Concept wise
- Relations - Definition
- Empty and Universal Relation
-
To prove relation reflexive, transitive, symmetric and equivalent
- Finding number of relations
- Function - Definition
- To prove one-one & onto (injective, surjective, bijective)
- Composite functions
- Composite functions and one-one onto
- Finding Inverse
- Inverse of function: Proof questions
- Binary Operations - Definition
- Whether binary commutative/associative or not
- Binary operations: Identity element
- Binary operations: Inverse
Transcript
Example 5 Show that the relation R in the set Z of integers given by R = {(a, b) : 2 divides a – b} is an equivalence relation. R = {(a, b) : 2 divides a – b} Check reflexive Since a – a = 0 & 2 divides 0 , eg: 0/2 = 0 ⇒ 2 divides a – a ∴ (a, a) ∈ R, ∴ R is reflexive. Check symmetric If 2 divides a – b , then 2 divides –(a – b) i.e. b – a Hence, If (a, b) ∈ R, then (b, a) ∈ R ∴ R is symmetric Check transitive If 2 divides (a – b) , & 2 divides (b – c) , So, 2 divides (a – b) + (b – c) also So, 2 divides (a – c) ∴ If (a, b) ∈ R and (b, c) ∈ R, then (a, c) ∈ R Therefore, R is transitive. Thus, R is an equivalence relation in Z.
