%% 
%%  A DANTE-Edition example
%% 
%%  Example 30-04-8 on page 607.
%% 
%%  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{201.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks-add}

\begin{document}
\def\F{x RadtoDeg dup dup cos exch 2 mul cos add exch 3 mul cos add}
\def\Fp{x RadtoDeg dup dup sin exch 2 mul sin 2 mul add exch
  3 mul sin 3 mul add neg}
\psset{plotpoints=1001,xunit=0.8,yunit=1}
\begin{pspicture}(-7.5,-1.8)(7.5,3.2)
  \psaxes{->}(0,0)(-7.5,-1.8)(7.5,3.2)
  \psplot[linewidth=3\pslinewidth]{-7}{7}{\F}
  \psset{linecolor=red}\multido{\n=-7+1}{8}{\psplotTangent{\n}{1}{\F}}
  \psset{linecolor=magenta}%
  \multido{\n=0+1}{8}{\psplotTangent[linecolor=blue,Derive=\Fp]{\n}{1}{\F}}
\end{pspicture}
\end{document}
