A = {1,2, 3}
R = {(1.2), (2, 1)}
Since (a, a) ∈ R ∀ a ∈ A R is not reflexive Now (1, 2) ∈ R ⇒ (2, 1) ∈ R and (2, 1) ∈ R ⇒ (1,2) ∈ R ∴ (a, b) ∈ R ⇒ (b, a) ∈ R ∀ (a, b) ∈ R ∴ R is symmetric Again (1, 2) ∈ R and (2, 1) ∈ R but (1, 1) ∉ R ∴ R is not transitive.
Determine whether each of the following relations are reflexive, symmetric and transitive :
(i) Relation R in the set A = {1, 2, 3,....., 13, 14} defined as
R = {(x, y) : 3 x – y = 0}
(ii) Relation R in the set N of natural numbers defined as R = {(x, y) : y = x + 5 and x < 4} (iii) Relation R in the set A = {1, 2, 3, 4, 5, 6} as R = {(x,y) : y is divisible by x} (iv) Relation R in the set Z of all integers defined as R = {(x,y) : x – y is an integer}
(v) Relation R in the set A of human beings in a town at a particular time given by
(a) R = {(x, y) : x and y work at the same place}
(b) R = {(x,y) : x and y live in the same locality}
(c) R = {(x, y) : x is exactly 7 cm taller than y}
(d) R = {(x, y) : x is wife of y}
(e) R = {(x,y) : x is father of y}
Mock Test Series
