Source
25 setxunit
7.5 setborder
90 setangle_repere
-5 4 setxrange
-4 3 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#   -2-65*x/42+5*x^3/42+2*x^2/7
} def
/g {setxvar
#rpn#   x-2
} def
gsave
   bleu
   0.75 setlinewidth
   continu
   {f} courbe
grestore
gsave
   rouge
   0.75 setlinewidth
   mixte
  xmin  .01 neg {g} Courbe
  .01  xmax {g} Courbe
grestore