Beamer talk

\documentclass{beamer}
\usetheme{Madrid}
\title{A Short Talk}
\subtitle{Slides with beamer}
\author{A. Speaker}
\date{October 2026}

\begin{document}
\begin{frame}
  \titlepage
\end{frame}

\begin{frame}{In this preview}
  The preview shows each frame as a slide, with its title and the theme's headline and footline (not its
  colors). Every \texttt{\textbackslash pause} and \texttt{<2->} step is shown at once here; Present
  steps through them. A full LaTeX run makes the PDF slides.
\end{frame}

\begin{frame}{Overlays}
  \begin{itemize}
    \item<1-> First, the question.
    \item<2-> Then, an idea.
    \item<3-> Finally, the answer.
  \end{itemize}
  \pause
  Revealed last.
\end{frame}

\begin{frame}{Two columns}
  \begin{columns}
    \begin{column}{0.5\textwidth}
      Left: words.
    \end{column}
    \begin{column}{0.5\textwidth}
      Right: $e^{i\pi} + 1 = 0$.
    \end{column}
  \end{columns}
\end{frame}

\begin{frame}{A math slide}
  \begin{block}{Theorem}
    For every $n \ge 1$, $\displaystyle \sum_{k=1}^{n} k = \frac{n(n+1)}{2}$.
  \end{block}
  \[ \det\begin{pmatrix} a & b \\ c & d \end{pmatrix} = ad - bc \]
\end{frame}
\end{document}