# ! Missing $inserted when try to using superscript in matrix in beamer I got the ! Missing$ inserted

mistake message when I try to use superscript inside a matrix environment in beamer. The following is my code

\begin{frame}
\begin{pmatrix}
\hat{\beta} \\ \hat{\beta}^{\dagger}
\end{pmatrix}
=
\begin{pmatrix}
U^\dagger & V^\dagger \\ U^\intercal & V^\intercal
\end{pmatrix}
\end{frame}


I tried using \begin{frame}[fragile] but it didn't work.

• You can't enter the pmatrix environment outside of math mode, You either need $ on each end of the pmatrix or $...$.delimiters. Apr 12 '16 at 17:43 ## 1 Answer Converting my comment to an answer, LaTeX has a both text and math modes. A number of commands intended for math mode use can only be invoked inside math mode. Attempts to invoke them in text mode will receive a "missing$ inserted" error.

To enter math mode in LaTeX, one can enter inline math with dollar delimiters $...$. Many argue a preferable way to do this is with the following delimiters: $$...$$. For displaystyle math, which prints its content, centered, on its own line, use the delimiters $...$.

There are also several additional environments that will place one inside display math mode. The equation environment does this. Using the amsmath package, there is the equation* variant (that does not number the equation), and also a series of environments in the align family.

The pmatrix environment of amsmath is just such an envioronment that expects to already be in math mode, upon invocation.

\documentclass{beamer}
\usepackage{amsmath}
\begin{document}
\begin{frame}
$\begin{pmatrix} \hat{\beta} \\ \hat{\beta}^{\dagger} \end{pmatrix} = \begin{pmatrix} U^\dagger & V^\dagger \\ U^\intercal & V^\intercal \end{pmatrix}$
\end{frame}
\end{document}