%% 
%%  A DANTE-Edition example
%% 
%%  Example 30-04-9 on page 608.
%% 
%%  Copyright (C) 2011 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[]{article}
\pagestyle{empty}
\setlength\textwidth{177.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks-add}

\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}
