Арифметическое выражение С++ Builder

//---------------------------------------------------------------------------
 
#include <vcl.h>
#pragma hdrstop
 
#include "Unit1.h"
#include <math.h>
#include <stdlib.h>
 
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button1Click(TObject *Sender)
{int n,z;
 n=StrToInt(Form1->Edit3->Text);
 StringGrid1->ColCount=n+1;
 StringGrid1->RowCount=2;
 StringGrid1->FixedCols=1;
 StringGrid1->FixedRows=1;
 StringGrid1->Cells[0][0]="Масив";
    for(z=0;z<=n;z++)
   StringGrid1->Cells[z+1][0]="z="+IntToStr(z+1);
   StringGrid1->Cells[0][1]="Елементи";
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button2Click(TObject *Sender)
{  int n,z,x,y;
   float  e[10];
   n=StrToInt(Form1->Edit3->Text);
   x=StrToInt(Form1->Edit1->Text);
   y=StrToInt(Form1->Edit2->Text);
      for(z=0;z<n;z++)
       {
       e[z]=(pow((cos(x)-sin(y)),3)/(sqrt(tan(x))))+pow(log(x*y*z),2);
       StringGrid1->Cells[z+1][1]=FloatToStr(e[z]);
        }
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::BitBtn1Click(TObject *Sender)
{
exit(1);        
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::FormCreate(TObject *Sender)
{
Edit1->Clear();
Edit2->Clear();
Edit3->Clear();
}
//---------------------------------------------------------------------------