Let A = {1, 2, 3, 4, 6}. Let R be the relation on A defined by
Question:

Let $A=\{1,2,3,4,6\}$. Let $R$ be the relation on $A$ defined by

$\{(a, b): a, b \in A, b$ is exactly divisible by $a\}$.

(i) Write R in roster form

(ii) Find the domain of R

(iii) Find the range of R.

Solution:

$\mathrm{A}=\{1,2,3,4,6\}, \mathrm{R}=\{(a, b): a, b \in \mathrm{A}, b$ 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 $R=\{1,2,3,4,6\}$