\documentclass[a4paper]{article}


\usepackage{amsmath}

\title{calcoli}
\author{bormoz}
\date{\today}


\begin{document}
\maketitle

$x= \int\int a(t) dt = \int\int a \sin(\alpha +\omega t) dt $

$a(t)=a\cdot\sin(\alpha +\omega t) $


\end{document}