Determine whether each of the following relations are reflexive, symmetric and transitive :
(iv) Relation R in the set Z of all integers defined as R = {(x,y) : x – y is an integer}
Relation R is in the set Z given by R = {(x,y) : x – y is an integer} (a) R is reflexive as ( x, x) ∈ R [∴ x – x = 0 is an integer]
(b) R is symmetric as (x,y) ∈ R ⇒ (y, x) ∈ A
[∵ x – y is an integer ⇒ y – x is an integer]
(c) R is transitive as (x, y), (y, z) ∈ R ⇒ (x, z) ∈ R
[∵ if x – y, y – z are integers, then (x – y) + (y – z) = x – z is also in integer]