# Is {(-1,2),(7,1)(0,-3)} a function?

$\left(x , f \left(x\right)\right) = \left\{\begin{matrix}- 1 & 2 \\ 7 & 1 \\ 0 & - 3\end{matrix}\right\}$ is a function
No value of $x$ has more than one corresponding value of $f \left(x\right)$
$\textcolor{w h i t e}{\text{XXXX}}$(which is the basic definition of a function).