-1 9 setxrange
-1 10 setyrange
tracerepere
marks

/f {
   setxvar
   x 3 exp 5 24 div mul
   x dup mul 21 8 div mul sub
   x 235 24 div mul add
   59 8 div sub
} def

1 8 (f) Courbe
[1 3 5 7 8] {dup f dashpoint} apply

setTimesItalic
   (C) 7.5 dup f ultext