%auteur : Peric
28.45 setxunit
7.5 setborder
90 setangle_repere
-4 6 setxrange
-5 5 setyrange
1 1 settkstep
.5 .5 setsubtkstep
1 1 setmkstep
ticks
marks
traceaxes
axesarrow
unites
/f {setxvar
#rpn#   x-1+2*x/(x^2+1)
} def
/g {setxvar
#rpn#   3*x-1
} def
/h {setxvar
#rpn#   x-1
} def
/k {setxvar
#rpn#   x
} def
/l {setxvar
#rpn#   x-2
} def
gsave
   bleu
   1.2 setlinewidth
   continu
   {f} courbe
grestore
gsave
   bleu
   0.5 setlinewidth
  % mixte
   pointilles
   {g} courbe
   {h} courbe
   {k} courbe
   {l} courbe
grestore

1 dup f plus2
-1 dup f plus2
(A) 1 dup f -0.1 add [1.5 dup] dctext
(B) -1 dup f -0.1 add [1.5 dup] dctext
<latex>
$y=3x-1$
</latex>
1.5 dup g [1 dup] {3 1 atan} uctexlabel
<latex>
$y=x$
</latex>
-3 dup k [1 dup] {45} uctexlabel
<latex>
$y=x-1$
</latex>
-3 dup h [1 dup] {45} uctexlabel
<latex>
$y=x-2$
</latex>
4 dup l [1 dup] {45} dctexlabel