%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 29-03-5 auf Seite 641.
%% 
%%  Copyright (C) 2016 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{145.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pstricks-add}
%StopShownPreambleCommands
\begin{document}
\def\Func{10 x div}\psset{unit=0.75}
\begin{pspicture}(-0.5,-0.5)(6.25,6.5)
  \psaxes[arrowscale=1.5]{->}(6.25,6.25)
  \psplot[linewidth=2pt,algebraic]{1.6}{5}{10/x}
  \psplotTangent[linewidth=.5pt,linecolor=red,
    algebraic]{3}{2}{10/x}
  \psplotTangent[linewidth=.5pt,linecolor=blue,
    algebraic,Derive=(x*x)/10]{3}{2}{10/x}
  \psline[linestyle=dashed](!0 /x 3 def \Func)%
    (!3 /x 3 def \Func)(3,0)
\end{pspicture}
\end{document}