Answer
The equation defines $y$ as a function of $x$.
The function can be written as $f(x)=3x^2-5$.
Work Step by Step
Solve for $y$ in terms of $x$ to have:
$3x^2=5+y
\\3x^2-5=y
\\y=3x^2-5$
The last equation is a rule that gives one value of $y$ for each value of $x$. Thus, it defines $y$ as a function of $x$
Therefore, the function can be written as:
$f(x)=3x^2-5$
