Let A = {1, 2, 3, 4, 6} and R = {(a, b) : a, b ϵ A, and a divides b}.
(i)Write R in roster form.
(ii)Find dom (R) and range (R).

Answer : Given: A = {1, 2, 3, 4, 6}

(i) R = {(a, b) : a, b ϵ A, and a divides b} R is Foster Form is,

R = {(1, 2), (1, 3), (1, 4), (1, 6), (2, 2), (2, 4), (2, 6), (3, 3), (3, 6), (4, 4), (6, 6)}

(ii) Dom(R) = {1, 2, 3, 4, 6}

Range(R) = {2, 3, 4, 6}