\begin{pspicture}*(-3.5,-3.5)(3.5,3.5)
      \psset{algebraic=true}
      \psgrid[subgriddiv=2, gridcolor = lightgray](-3.5,-3.5)(3.5,3.5)
    \psaxes{->}(0,0)(-3.5,-3.5)(3.5,3.5)

    \psplot[linecolor=red,linewidth=1pt]{-3}{3}{-(x-1)*(x+1) / EXP(x)}
  \end{pspicture}