On obtient ça :
\begin{center}
  \begin{boxedminipage}{.9\textwidth}
    \begin{flushleft}
      Soit :
      \begin{pspicture}[](-1,-1)(1,1)
        \parametricplot[linewidth=.5pt,plotstyle=ccurve]%
  {0}{360}{4 t mul sin 3 t mul sin}
  \psgrid[gridlabels=0pt](-1,-1)(1,1)
\end{pspicture} \quad le tracé de $x=\sin(4t), y=\sin(3t)$...
\end{flushleft}
\end{boxedminipage}
\end{center}
