%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 29-03-8 auf Seite 643.
%% 
%%  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{193.16928pt}
\setlength\parindent{0pt}
\usepackage{pstricks-add}
\def\pshlabel#1{\footnotesize#1}
\def\psvlabel#1{\footnotesize#1}
%StartShownPreambleCommands
\usepackage{pstricks-add}
%StopShownPreambleCommands
\begin{document}
\psset{xunit=2}
\def\FF{x dup mul} \def\dFF{x 2 mul}
\begin{pspicture}(-0.25,-0.5)(2,4)
  \psaxes[Dx=0.5,Dy=1]{->}(0,0)(2,3.75)
  \psplot[linewidth=1.5pt]{0}{2}{\FF}
  \psplotTangent{1}{1}{\FF}
  \psdot(! 1 /x 1 def \FF)
\end{pspicture}
\end{document}