\documentclass[12pt]{article}
\thispagestyle{empty}
\usepackage{hyperref}
\usepackage{amsmath}
\begin{document}
\huge{
$i \hbar \frac{\partial}{\partial t} \psi( \vec{r},t) = \frac{p^2}{2 m} \psi( \vec{r},t)$
}
\end{document}
