%Пример от Сергея В. Знаменского
\documentclass{article}
\usepackage[koi8-r]{inputenc}
\usepackage[russian]{babel}
\usepackage[metapost]{mfpic}
\opengraphsfile{graph-mfp}
\begin{document}
\pagestyle{empty}
\mfpic[1][57.2]{-100}{300}{-1.2}{1.2}
\axes
\xmarks{-90,90,180,270}
\ymarks{-1,1}
\dotted\function{-90,270,4.5}{sind(x)}
\dashed\function{-90,270,4.5}{cosd(x)}
\function{-50,50,10}{tand(x)}
\function{130,230,10}{tand(x)}
\endmfpic
\closegraphsfile

\end{document}
