[Tex/LaTex] \tau \epsilon \chi ! Missing $ inserted

Question

Beginner here with an issue on a simple presentation using beamer

\documentclass{beamer}

\begin{document}
\begin{frame}
  \tau \epsilon \chi
\end{frame}
\end{document}

The above fails with the message "! Missing $ inserted." and waits for me to do something when converting to pdf. I have tried adding the instruction \usepackage[utf8]{inputenc} and also \usepackage[greek]{babel}. I have not seen references either to needing to use any other package. What is exactly I am missing?

Answer 1

You need to put mathematics inside math-mode, which you do by enclosing it in $...$, for in-line equations, or \[...\] for displayed equations:

\documentclass{beamer}

\begin{document}
\begin{frame}
  $\tau \epsilon \chi$

 For displayed equations:
 \[ \tau \epsilon \chi \]

\end{frame}
\end{document}