# \dot{x} and beamer

Using \dot{X} with beamer ends up with an x with an omega on it!! My code:

\documentclass[15pt, slidestop]{beamer}

\usepackage[T1]{fontenc}
\usepackage[brazil]{babel}
\usepackage[utf8]{inputenc}
\usepackage{ae}

\usepackage{graphicx}
\usepackage{amsmath,amssymb}
\usepackage{fancyvrb}
\usepackage[normalem]{ulem}
\usepackage{float}
\usepackage{colortbl}
\usepackage{bbm}
\usepackage{color}
\usepackage{algorithmic}
\usepackage{rotating}
\usepackage{algorithm}
\usepackage{multicol}
\usepackage{fourier}

\begin{document}

\frame{
\frametitle{}

\begin{displaymath}
\dot{x}  =  A x(t) + B u(t)
\end{displaymath}

}
\end{document}


Any help?

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Your example works on my machine (i.e. I get a dot, not an omega). – Ian Thompson Sep 11 '12 at 13:22
Same on mine (Mac OS X Lion, TeX Live 2012). Could you pare down the list of packages to a minimal list that produces the error, and then say which version of each you are using (put \listfiles at the start of your document). – Loop Space Sep 11 '12 at 13:23
Just a remark: package ae is rather old and should not be used today (see l2tabu). – Kurt Sep 11 '12 at 13:32
If you really want to use the Fourier fonts for your presentation, then add the professionalfont option to \documentclass. – egreg Sep 11 '12 at 13:55
@egreg: No! The class option is depreciated. The font theme is the correct way to invoke this (see tex.stackexchange.com/a/26829/86 for some details). – Loop Space Sep 11 '12 at 14:16

Beamer does some stuff internally with fonts. If you load your own font package, you might want to switch that off. The font theme professionalfonts is provided for this functionality.

\documentclass{beamer}
\usefonttheme{professionalfonts}

\usepackage{fourier}

\begin{document}

\begin{displaymath}
\dot{x}  =  A x(t) + B u(t)
\end{displaymath}

\end{document}


Produces:

-