25 setxunit
7.5 setborder
90 setangle_repere
-5 5 setxrange
-1 6 setyrange
/quadrillagegray 0.4 def
1 setquadrillagexstep
1 setquadrillageystep
quadrillage
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
ticks
subticks
marks
traceaxes
axesarrow
unites
/f {setxvar
#rpn#   x^2-2x-5
} def
gsave
   noir
   1 setlinewidth
   continu
  5 neg  5 {f} Courbe
grestore