50 setxunit
3 setborder
90 setangle_repere
-6 6 setxrange
-6 6 setyrange
1 1 settkstep
.5 .5 setsubtkstep
1 1 setmkstep
ticks
marks
traceaxes
axesarrow
unites
/f {setxvar
#rpn#   1/x
} def
/f' {setxvar
#rpn#   -1/x^2
} def
/g {setxvar
#rpn#   x
} def
/h {setxvar
#rpn#   -x
} def
gsave
   noir
   .75 setlinewidth
   continu
  6 neg  0.01 neg {f} Courbe
  0.01  6 {f} Courbe
grestore
gsave
   rouge
   .75 setlinewidth
   mixte
  6 neg  6 {g} Courbe
6 neg  6 {h} Courbe
grestore
2 settailletangente
-1 (f) tangente
1 (f) tangente