416.666666666667 setwidth
250 setheight
7.5 setborder
-10 10 setxrange
-6 6 setyrange
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
ticks
subticks
marks
traceaxes
axesarrow
unites
jpegmode
/f {setxvar
    8 x mul 1 sub x 2 exp 1 add div
} def
/g {setxvar
    1 x div
} def
gsave
   bleu
   .75 setlinewidth
   continu
   {f} courbe
grestore