\def\F{x 3 exp 3 div x sub 2 3 div add .0001 add}
\psaxes{->}(0,0)(-3,-1)(3,4)
\psplot[linewidth=2\pslinewidth, linecolor=gray]{-2.5}{2.5}{\F}
\psset{PointSymbol=*}
\pstGeonode[PosAngle={-45,0}](0,-.2){N}(2.5,1){M}
\pstLineAB[nodesepA=-3cm]{N}{M}
\psset{PointSymbol=o}
\pstInterFL{\F}{N}{M}{2}{A}
\pstInterFL[PosAngle=90]{\F}{N}{M}{0}{A'}
\pstInterFL{\F}{N}{M}{-2}{A''}