25 setxunit -5 5 setxrange -4 4 setyrange 1 1 settkstep .5 .5 setsubtkstep 2 2 setmkstep ticks %marks traceaxes axesarrow /f {setxvar 1 x 2 exp sub sqrt } def /g {setxvar 4 x 2 exp sub sqrt neg } def /ff {setxvar 6 x 2 exp sub sqrt } def /gg {setxvar 10 x 2 exp sub sqrt neg } def gsave noir 1.75 setlinewidth continu 1 neg 1 {f} Courbe grestore gsave noir 1.75 setlinewidth continu 2 neg 2 {g} Courbe grestore gsave noir 1.75 setlinewidth continu 2.449 2.449 neg {ff} Courbe grestore gsave noir 1.75 setlinewidth continu 3.162 3.162 neg {gg} Courbe grestore