-5 5 setxrange -7 5 setyrange -5 5 setyrange 30 setxunit gsave masque quadrillage /f { exch pop dup mul 1 add } def .5 setlinewidth /arrowscale {.5 dup} def .4 setgray {f} .25 .25 .1 champvecteur /arrowscale {.75 dup} def .7 setlinewidth noir tracerepere .5 setlinewidth orange %% on represente quelques solutions -7 1 7 { /i exch def [{f} i 1 .01 euler] ligne } for grestore #tex# $y' = 1 + y^2$ 0 -6 [2 dup] cctexlabel