Как исправить программу

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, StdCtrls;
 
type
  TForm1 = class(TForm)
    Button1: TButton;
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    Label3: TLabel;
    Edit3: TEdit;
    StringGrid1: TStringGrid;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
function f(a, x: real):double;
begin
  result:=(1+sin(2*A*X))/(1+sqr(A*x));
end;
 
procedure TForm1.Button1Click(Sender: TObject);
var a, x, y, xn, xk, hx: real;
i, k, n: integer;
begin
 
  with StringGrid1 do
  begin
    fixedcols:=0;
    colcount:=2;
    rowcount:=k+2;
    cells[0,0]:='x';
    cells[1,0]:='y';
  end;
 
  a:=strtoint(edit1.Text);
  xn:=strtofloat(edit2.Text);
  xk:=strtofloat(edit3.Text);
  hx:=0.1;
  i:=1;
  k:=0;
  x:=xn;
  for k := 0 to n + 1 do
  begin
    x:=xn+k*hx;
    with StringGrid1 do
    begin
      cells[0,k+1]:=FormatFloat('0.00', x);
      cells[1,k+1]:=FormatFloat('0.00', y);
    end;
  end;
 
 
end;
 
end.

for k:=1 to StringGrid1.RowCount-1 do
Series1.AddXY(strtofloat(StringGrid1.Cells[0,k]),strtofloat(StringGrid1.Cells[1,k]),'',clRed);

uses Chart;
procedure TForm3.FormCreate(Sender: TObject);
var
  ch: TChart;
  gs: TFastLineSeries;
  i: Integer;
begin
  ch := TChart.Create(self);
  ch.Align := alClient;
  ch.Parent := Self;
  gs := TFastLineSeries.Create(ch);
  Randomize;
  for i := 0 to 10 do
  begin
    gs.Add(Random(20), IntToStr(i), clNavy);
  end;
  ch.AddSeries(gs);
end;