\documentclass{article}
\begin{document}
This is my first LaTeX document. 
\begin{equation}
  a^2 + b^2 = c^2 
\end{equation}
\[
\begin{pmatrix}
\alpha& \beta^{*}\\
\gamma^{*}& \delta
\end{pmatrix}
\]
\end{document}