Посоветуйте с графиком

procedure TForm1.Button1Click(Sender: TObject);
const
  mast = 50;
 
var
  h0, w0: integer;
  x, y, a , b: real;
 
begin
  Image1.Canvas.Pen.Color := clWhite;
  Image1.Canvas.Rectangle(0, 0, ClientWidth, ClientHeight);
  //Ñ÷èòûâàåì êîýôèöåíòû
  a := StrToInt(edit1.Text);
  b := StrToInt(edit2.Text);
 
  //Íàõîäèì öåíòð
  w0 := Image1.ClientWidth div 2;
  h0 := Image1.ClientHeight div 2;
 
  //Ðèñóåì ëèíèè
  with Image1.Canvas do
    begin
      //Öâåò ëèíèè
      Pen.Color := clGreen;
      Pen.Width := 2;
 
      MoveTo(w0, 0);
      LineTo(w0, ClientHeight);
 
      MoveTo(0, h0);
      LineTo(ClientWidth, h0);
    end;
 
  //Ñòðîèì ãðàôèê
  Image1.Canvas.Pen.Color := clRed;
  Image1.Canvas.Pen.Width := 1;
 
  x := -10;
  y := 2 * x + 5;
  Image1.Canvas.MoveTo(Trunc(x * mast) + w0, Trunc(y * mast) + h0);
  repeat
    x := x + 0.1;
    y := 2 * x + 5;
    Image1.Canvas.LineTo(Trunc(x * mast) + w0, Trunc(y * mast) + h0);
  until x >= 10;
 
  if ((a <= w0) or ( a >= w0) or (a > w0) or (a < w0) and
      (b >= h0) or (b <= h0) or (b > h0) or (b < h0))
    then
      begin
        Image1.Canvas.LineTo(Trunc(x * mast) + w0, Trunc(y * mast) + h0);
      end;
end;
 
end.