Program parabola;
uses GraphABC;
Var i,x0,y0,x1,y1,k,x1a,y1a: integer;
x,y,x2,y2: real;
Begin
setWindowSize(640,400);
x0:=320; y0:=360; k:=25;
line(x0,20,x0,380); line(20,y0,620,y0);
line(x0,20,x0-10,30); line(x0,20,x0+10,30);
line(630,y0,620,y0-10); line(630,y0,620,y0+10);
for i:=-5 to 5 do
begin
line(x0+(i*k),y0-10,x0+(i*k),y0+10);
textout(x0+(i*k),y0+10,inttostr(i));
end;
for i:=-5 to 5 do
begin
line(x0-10,y0+(i*k),x0+10,y0+(i*k));
if i<>0 then textout(x0+10,y0+(i*k),inttostr(-i));
end;
setPenColor(cllime);
x:=-10;
While x<=10 do
begin
y:=sqr(x)*x+3*(sqr(x))-9*x-5+cos(x);
x1:=trunc(x0+x*k); y1:=trunc(y0-y*k);
circle(x1,y1,2);
x:=x+0.01;
end;
End.