[tex]\bf \qquad \textit{parabola vertex form}\\\\
\begin{array}{llll}
y=a(x-{{ h}})^2+{{ k}}\\\\
x=a(y-{{ k}})^2+{{ h}}
\end{array} \qquad\qquad vertex\ ({{ h}},{{ k}})\\\\
-------------------------------\\\\
-x^2\implies -(x-\stackrel{h}{0})^2\stackrel{k}{+0}[/tex]
