Question

what is equivalence relation?

Answer 1

a relation between elements of a set which is reflexive, symmetric, and transitive and which defines exclusive classes whose members bear the relation to each other and not to those in other classes.

Answer 2

Suppose a relation R is defined on the set of natural number N...
€ = Belongs to

(1) => Let a € N be any arbitrary element
If a R a Or (a , a) € R.... R is a reflexive Relation

(2) => If ( a , b ) € R then ( b , a ) € R...Relation R is a symmetric relation.

(3) => If ( a, b ) and ( c, d ) € R then ( a , c ) € R...R is a transitive relative..

If a Relation R is Reflexive , Symmetric and transitive Then it is an Equivalence relation...