\input preamble.tex

\Defnum(\n,-1)

% ---------------------------------------------------------------------------
\begin{document}
\unitlength1.4cm

\begin{center}
{\Huge\bf{Hippopede Curves}}
\bigskip

\begin{lapdf}(12,14)(-6,-7)
 \Polgrid(1,4)(6)
 \def\Px(#1,#2){\Sin(#1,#2) \Dmul(#2,#2) #2=\n#2
  \Dsub(#2,10) #2=-#2 \Sqrt(\Np#2,#2) #2=1.897#2}
 \Whilenum{\n<10}{\Add(\n,1) \Stepcol(0,23,2) \Pplot(150)(0,2) \Stroke}
\end{lapdf}

$r(\phi)=6 \cdot \sqrt{1-c \cdot \sin^2\phi}$ with ($c=0,1 \dots 1,0$)
\end{center}
\end{document}
