График естественной механической характеристики АС двигателя в TImage

unit Unit1;
 
interface
 
uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.ExtCtrls;
 
type
  TForm1 = class(TForm)
    Image1: TImage;
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Edit3: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
const mash=10;
var
a,b,c:integer;
x,y:real;
x0,y0:integer;
i:integer;
begin
a:=strtoint(edit1.Text);
b:=strtoint(edit2.Text);
c:=strtoint(edit3.Text);
x0:=image1.Width div 2;
y0:=image1.Height div 2;
 
  with image1.Canvas  do
  begin
    Pen.Color:=clred;
    MoveTo(x0,0);
    LineTo(x0,image1.Height);
 
    MoveTo(0,y0);
    LineTo(image1.Width,y0);
 
  end;
 
 
 
 
  x:=-10;
  y:=x*x;
  image1.Canvas.LineTo(trunc(x),trunc(y));
  repeat
  y:=x*x;
  image1.Canvas.LineTo(trunc(x*mash)+x0,-trunc(y*mash)+y0);
  x:=x+0.1
  until x>=10;
end;
 
end.

// здесь все без изменений
 
  X := -10;
  Y := X * X;
  Image1.Canvas.MoveTo(trunc(X * mash) + x0, -trunc(Y * mash) + y0);
  repeat
    Y := X * X;
    Image1.Canvas.LineTo(trunc(X * mash) + x0, -trunc(Y * mash) + y0);
    X := X + 0.1
  until X >= 10;

var
  x, y: integer;
begin
  y := Image1.Width; //øèðèíà
  x := Image1.Height; //âûñîòà
 
  Image1.Canvas.MoveTo(y div 2, 0); //íà÷àëî ëèíèè
  Image1.Canvas.LineTo(y div 2, x * 2); //êîíåö ëèíèè
 
  Image1.Canvas.MoveTo(0, x div 2);
  Image1.Canvas.LineTo(y, x div 2);
end;