%%% les bornes sur les axes
/xmin -3.2 def
/xmax 1.1 def
/ymin -1 def
/ymax 4.5 def

.5 .5 setquadrillagestep

/f {
   dup dup dup mul     % x, x, x^2
   2 div add
   exch
   dup Exp mul add
} def

/f' {pop 0} def

/g {
   dup dup mul     % x, x^2
   2 div add
}  def

quadrillage

.7 setlinewidth
traceaxes
ticks
-3 xmark
-1 xmark
1 xmark
1 ymark
axesarrow

1.2 setlinewidth
{g} courbe

setTimesItalic
   (O) 0 0 drtext
   (x) Xmax 0 ultext
   (y) 0 Ymax dltext
   (P) Xmax dup g ultext