2 setxyrapport
25 setxunit
-4 4 setxrange
-17 9 setyrange
1 2 settkstep
.5 1 setsubtkstep
2 4 setmkstep
ticks
subticks
marks
traceaxes
unites
/f {setxvar
#rpn#   x^4-10*x^2+9
} def
bleu
.75 setlinewidth
{f} courbe