Source
100000 setxyrapport
50 setxunit
7.5 setborder
90 setangle_repere
-2 6 setxrange
-25000 1000000 setyrange
1 50000 settkstep
.5 .5 setsubtkstep
1 50000 setmkstep
ticks
marks
traceaxes
axesarrow
unites
/f {setxvar
#rpn#   1000000*Exp(-2*x)
} def
/g {setxvar
#rpn#   2000000*(Exp(-2*x)-Exp(-3*x))
} def
/h {setxvar
#rpn#   1000000*(1+2*Exp(-3*x)-3*Exp(-2*x))
} def

gsave
   bleu
   .75 setlinewidth
   continu
  0  6 {f} Courbe
grestore
gsave
   bleu
   .75 setlinewidth
   continu
  0  6 {h} Courbe
grestore

gsave
   rouge
   .75 setlinewidth
   continu
  0  6 {g} Courbe
grestore