\begin{pspicture}(-5,-5)(5,5) \psset{xunit=1 cm, algebraic=true} \psaxes{->}(0,0)(-5,-5)(5,5) % Trouver antécédents \psline[linecolor=green,linewidth=1pt]{-}(0,1)(1,1) \psline[linecolor=green,linewidth=1pt]{-}(1,1)(1,0) \psline[linecolor=green,linewidth=1pt]{-}(0,0.5)(2,0.5) \psline[linecolor=green,linewidth=1pt]{-}(2,0.5)(2,0) \psline[linecolor=green,linewidth=1pt]{-}(0,0.25)(4,0.25) \psline[linecolor=green,linewidth=1pt]{-}(4,0.25)(4,0) \psline[linecolor=green,linewidth=1pt]{-}(0,-1)(-1,-1) \psline[linecolor=green,linewidth=1pt]{-}(-1,-1)(-1,0) \psline[linecolor=green,linewidth=1pt]{-}(0,-0.5)(-2,-0.5) \psline[linecolor=green,linewidth=1pt]{-}(-2,-0.5)(-2,0) \psline[linecolor=green,linewidth=1pt]{-}(0,-4)(-0.24,-4) \psline[linecolor=green,linewidth=1pt]{-}(-0.25,-4)(-0.25,0) % Images \psline[linecolor=red,linewidth=1.5pt]{-}(0,1)(0,-4.8) %antécédents \psline[linecolor=red,linewidth=2pt]{-}(1,0)(4.8,0) \psline[linecolor=red,linewidth=2pt]{-}(0,0)(-4.8,0) % la fonction inverse \psplot[linecolor=black,linewidth=1.5pt]{-5}{-0.2}{1/x} \psplot[linecolor=black,linewidth=1.5pt]{0.2}{5}{1/x} \end{pspicture}