1 setxyrapport 90 setxunit 7.5 setborder 90 setangle_repere -0.25 5 setxrange -0.5 7 setyrange [1 1 .5 .5 .1 .1] {orange} Quadrillage /quadrillagegray 0.4 def 1 setquadrillagexstep 1 setquadrillageystep quadrillage 1 1 settkstep .5 .5 setsubtkstep 1 1 setmkstep ticks subticks marks traceaxes axesarrow unites /f {setxvar #rpn# x+5/x-1 } def /g {setxvar #rpn# 4+1/x } def gsave noir .75 setlinewidth continu {f} courbe grestore gsave bleu .65 setlinewidth continu {g} courbe grestore gsave rouge continu /hstep 2 store /hangle 45 store 1 4 {f} {g} Hachcourbes grestore