Question

Let A = {1, 2, 3, 4, 6}. Let R be the relation on A defined by $\left\{\right(a,b):a,bϵA,b$ is exactly divisible by a}.

(i) Write R in roster form.

(ii) Find the domain of R.

(iii) Find the range of R.

Answer 1

Here A = {1, 2, 3, 4, 6}.

We have to form a set of ordered pairs (a, b) where b is exactly divisible by a.

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

(2, 4), (2, 6), (3, 3), (3, 6), (4, 4), (6, 6)}

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

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