100 setxyrapport
20 setxunit
10 setborder
90 setangle_repere
-1.5 12 setxrange
-90 1200 setyrange
/quadrillagegray 0.4 def
1 setquadrillagexstep
100 setquadrillageystep
quadrillage
2 100 settkstep
.5 .5 setsubtkstep
2 100 setmkstep
ticks
marks
traceaxes
axesarrow
/f {setxvar
#rpn#   (22-2*x)*(28-2*x)*x
} def
gsave
   bleu
   .75 setlinewidth
   continu
 0 11  {f} Courbe
grestore