#### Answer

$y$ is a function of $x$.

#### Work Step by Step

Solve for $y$ in terms of $x$ to obtain:
$\begin{array}{ccc}
&3x^2-y &= &5
\\&-y &= &-3x^2+5
\\&-1(-y) &= &-1(-3x^2+5)
\\&y &= &3x^2-5
\end{array}$
The last equation above will give only one $y$ value for each value of $x$.
Thus, the equation represents $y$ as a function of $x$.