# How do you determine if (-1, 2), (-1, 3), (2, 4) is a function?

$\left(x , f \left(x\right)\right) \in \left\{\begin{matrix}- 1 & 2 \\ - 1 & 3 \\ 2 & 4\end{matrix}\right\}$ is not a function since There is more than one value for $f \left(- 1\right)$
$f \left(- 1\right) \rightarrow 2$ and $3$