30 setxunit 7.5 setborder 90 setangle_repere -5 5 setxrange -1 6 setyrange 1 1 settkstep .5 .5 setsubtkstep 1 1 setmkstep ticks marks traceaxes axesarrow unites /f {setxvar #rpn# x^2-4 } def /g {setxvar #rpn# 4-x^2 } def /h {setxvar #rpn# (x-4)^2 } def /u {setxvar #rpn# 5 } def gsave noir .75 setlinewidth continu 3 neg 2 neg {f} Courbe 2 3 {f} Courbe grestore gsave noir .75 setlinewidth continu 2 neg 2 {g} Courbe grestore gsave noir .75 setlinewidth continu 3 5 {h} Courbe grestore gsave noir .75 setlinewidth continu -5 -3 {u} Courbe grestore