Answer
Sample answer:
$\{(1,1), (2,1)\}$
Work Step by Step
For a relation to be a function, we can not have two ordered pairs with the the same first component, and different second components.
E.g.,$ \{(1,1),(1,2)\}$ is not a function, there are two different ordered pairs have the same first component.
It is not forbidden for two different first components to have the same second component,
$\{(1,1), (2,1)\}$ is a function ... no two different ordered pairs have the same first component.
However, if we reverse the components, $\{(1,1),(1,2)\}$ is not a function, as we said in the first paragraph.
Sample answer:
$\{(1,1), (2,1)\}$
