import graph;

size(10cm,0);

real xmin=-4,xmax=4;
real ymin=-2,ymax=10;

// Définition de la fonction
real f(real x) {return x^2;}

// Construction de points sous forme de croix
path Cf1=graph(f,xmin,xmax,n=16);
marker cross=marker(scale(4)*rotate(45)*cross(4),1bp+red);
cross.mark(Cf1); 

// Définition et construction de la courbe
path Cf2=graph(f,xmin,xmax,n=400);
draw(Cf2,linewidth(1bp));

ylimits(-2.5,10,Crop);

xaxis(Label("$x$",position=EndPoint, align=NE),
      xmin=xmin,xmax=xmax,
      Ticks(scale(.7)*Label(align=E),
            NoZero,
            begin=false,beginlabel=false,
            end=false,endlabel=false,
            Step=1,step=.25,
            Size=1mm, size=.5mm,
            pTick=black,ptick=gray),
            Arrow);

yaxis(Label("$y$",position=EndPoint, align=NE),
      ymin=ymin,ymax=ymax,
      Ticks(scale(.7)*Label(),
            NoZero,
            begin=false,beginlabel=false,
            end=false,endlabel=false,
            Step=1,step=.25,
            Size=1mm, size=.5mm,
            pTick=black,ptick=gray),
      Arrow);

shipout(bbox(2mm,Fill(white)));