# Change the sans serif math font

I would like to change the sans serif math font to, say, Kurier, while keeping the roman font as the default. In other words, I'd like to change the font that is used with \mathsf whithout affecting the behaviour of the other math commands. Any suggestion?

Look in the file kurier.sty and you'll find the lines (not in the same places)

\DeclareOption{regular}{\renewcommand{\rmdefault}{kurier}}
\SetMathAlphabet{\mathsf}{kurier}{OT1}{\rmdefault}{m}{n}
\SetMathAlphabet\mathsf{kurierbold}{OT1}{\rmdefault}{bx}{n}


that tell you how to do in your case. The first line reveals the font family internal name, the other two what's used for \mathsf. So, add

\DeclareMathAlphabet{\mathsf}{OT1}{kurier}{m}{n}
\SetMathAlphabet{\mathsf}{bold}{OT1}{kurier}{bx}{n}


to your document preamble. The first declaration tells LaTeX that \mathsf must use Kurier, changing it into bold when the math version is bold.

For XeTeX you can say in the preamble something like

\usepackage{mathspec}
\setmathsf{Liberation Sans}