When I latexed the example below I did not get "X" in the outcome of the file. Is there a solution for this?
Thanks a lot for the help.
Code: Select all
\documentclass{article}
\usepackage{amsmath,bm}
\usepackage[cp1256]{inputenc}
\usepackage[arabic,english]{babel}
\begin{document}
$\frac{d}{dt}[\bm{r}(t)\times\bm{s}(t)]=\bm{r}'(t)\times\bm{s}(t)+\bm{r}(t)\times\bm{s}'(t)$
\end{document}