Question:
Let $A=\{(x, y): x+3 y=12, x \in N$ and $y \in N\}$
(i) Write R in roster form.
(ii) Find dom (R) and range (R).
Solution:
Given: $A=\{(x, y): x+3 y=12, x \in N$ and $y \in N\}$
(i) So, R in Roster Form is,
$R=\{(3,3),(6,2),(9,1)\}$
(ii) $\operatorname{Dom}(R)=\{3,6,9\}$
Range(R) $=\{1,2,3\}$