Question:
Let $R=\left\{\left(a, \frac{1}{a}\right): a \in N\right.$ and $\left.1
Find the domain and range of $R$.
Solution:
$\operatorname{dom}(R)=\{2,3,4\}$ and range $(R)=\left\{\frac{1}{2}, \frac{1}{3}, \frac{1}{4}\right\}$