25 setxunit
7.5 setborder
90 setangle_repere
-3 3 setxrange
-7 5 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^3-3*x-1
} def
/f' {setxvar
#rpn#   3*x^2 - 3
} def
gsave
   noir
   .75 setlinewidth
   continu
   {f} courbe
grestore

2.8 settailletangente
 -1 (f) tangente
 1 (f) tangente
9 settailletangente
 0 (f) tangente