Ошибка: "0,1 is not a valid integer value"

#include <vcl.h>
#pragma hdrstop
#include <math.h>
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::FormCreate(TObject *Sender)
{
Edit1->Text="0,1";
Edit2->Text="1,0";
Edit3->Text="10";
Edit4->Text="0,1";
Memo1->Lines->Add("ИПР №1");
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
Memo1->Clear();       
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
double a, b, x, y, h, r, s;
 int n, k, fact, zn=-1;
 a = StrToFloat(Edit1->Text);
 b = StrToFloat(Edit2->Text);
 n = StrToInt(Edit3->Text);
 h = StrToFloat(Edit4->Text);
for(x = a; x<=b; x+=h){
Memo1->Lines->Add("При x= "+FloatToStrF(x,ffFixed,8,2));
y=sin(x);
Memo1->Lines->Add("Y(x)= "+FloatToStrF(y,ffFixed,8,6));
for( int i = 1; i <= (k*2 + 1); i++ )
for (k=0; k<=n; k++){
if(k==0) fact = 1;
else fact*=k;
s+=pow(x,2+1)/fact;
}
Memo1->Lines->Add(" S(x)= "+FloatToStrF(s,ffFixed,8,6));
r=fabs(y-s);
Memo1->Lines->Add(" |Y(X)-S(x)|= "+FloatToStrF(r,ffFixed,8,6));
}
}
 
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop
#include <Math.h>
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
 
const double defA = 0.1, defB = 1.0, defH = 0.1;
const int defN = 10;
 
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
  edt_A->Text = FloatToStrF(defA, ffFixed, 8, 2);
  edt_B->Text = FloatToStrF(defB, ffFixed, 8, 2);
  edt_H->Text = FloatToStrF(defH, ffFixed, 8, 2);
  edt_N->Text = IntToStr(defN);
  Memo1->Clear();
}
//---------------------------------------------------------------------------
long double fact(int n)
{
  if(n < 0) return 0;
  if(n == 0) return 1; else return n * fact(n - 1);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button2Click(TObject *Sender)
{
  Memo1->Clear();
}
//---------------------------------------------------------------------------
double S_X(double x, int n)
{
  double s = 0;
  for(int i = 0; i < n; i++)
    s += (pow(-1, i))*(pow(x, 2*i + 1) / fact(2 * i + 1));
  return s;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
  int i = 1;
  double a = StrToFloatDef(edt_A->Text, defA),
         b = StrToFloatDef(edt_B->Text, defB),
         h = StrToFloatDef(edt_H->Text, defH),
         x;
  int n = StrToIntDef(edt_N->Text, defN);
  for(x = a; x <= b; x += h)
   {
     Memo1->Lines->Add(String().sprintf("Шаг %d:\tХ = %.2f", i++, x));
     Memo1->Lines->Add(String().sprintf("\tY(x) = %.8f\t\tS(x) = %.8f", sin(x), S_X(x, n)));
     Memo1->Lines->Add(String().sprintf("\t|Y(x) - S(x)| = %.8f", fabs(sin(x) - S_X(x, n))));
   }
}
//---------------------------------------------------------------------------