Функция пользователя.

#include <vcl.h>
#pragma hdrstop
#include "math.h"
#include "Unit1.h"
typedef double (*TFun)(double);
double fun1(double);
double fun2(double);
void Out_Rez(TFun, double, double, double, TMemo*);
//---------------------------------------------------------------------------
#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="0,1";
Edit4->Text="";
Memo1->Clear();
Memo2->Clear();
RadioGroup1->ItemIndex=0;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{ double a, b, h;
        a = StrToFloat(Edit1->Text);
            b = StrToFloat(Edit2->Text);
            h = StrToFloat(Edit3->Text);
 
 
           switch(RadioGroup1->ItemIndex) {
                case 0: Out_Rez (fun1,a,b,h,Memo1); break;
                case 1: Out_Rez (fun2,a,b,h,Memo2); break; }
 
}
 double fun1( double r,double s, double k,double m){
  r = s = 1;
  for(k = 1; k<=5; k++){
  r = cos(M_PI/4.0)*r*m/k;
  s+=r; }
        return s;
}
double fun2(double t) {
        return exp(t*cos(M_PI/4.0))*cos(t*sin(M_PI/4.0));}
 
void Out_Rez (TFun f,double xn,double xk,double h,TMemo *mem) {
       for(double x=xn; x<=xk; x+=h)
              mem->Lines->Add(" x = "+FloatToStrF(x,ffFixed,8,2)+
                                 "  y = "+FloatToStrF(f(x),ffFixed,8,4));
}
 
 
//---------------------------------------------------------------------------