Let $A = \{1, 2, 3, \ldots, 14\}$. Define a relation $R$ from $A$ to $A$ by $R = \{(x, y) : 3x - y = 0, \text{ where } x, y \in A\}$. Write down its domain,codomain,and range.

(N/A) The relation $R$ from $A$ to $A$ is given by $R = \{(x, y) : 3x - y = 0, \text{ where } x, y \in A\}$.
This can be rewritten as $R = \{(x, y) : y = 3x, \text{ where } x, y \in A\}$.
For $x = 1, y = 3 \in A$.
For $x = 2, y = 6 \in A$.
For $x = 3, y = 9 \in A$.
For $x = 4, y = 12 \in A$.
For $x = 5, y = 15 \notin A$.
Thus,$R = \{(1, 3), (2, 6), (3, 9), (4, 12)\}$.
The domain of $R$ is the set of all first elements of the ordered pairs,which is $\{1, 2, 3, 4\}$.
The codomain of the relation $R$ is the set $A = \{1, 2, 3, \ldots, 14\}$.
The range of $R$ is the set of all second elements of the ordered pairs,which is $\{3, 6, 9, 12\}$.