Bisection Method - Program

#include<stdio.h>
#include <math.h>
#include<conio.h>
#define ESP 0.001
#define F(x) (x)*(x)*(x)+(x)*(x)+(x)-7
void main()
{
  int i = 1;
  float x0,x1,x2;
  double f1,f2,f0,t;
  clrscr();
  printf("\nEnter the value of x0: ");
  scanf("%f",&x0);

  printf("\nEnter the value of x1: ");
  scanf("%f",&x1);
  printf("\n__________________________________________________________________\n");
  printf("\nIteration\t x0\t       x1\t x2\t   f0\t   f1\t   f2");
  printf("\n___________________________________________________________________\n");
  do
  {
  x2=(x0+x1)/2;
  f0=F(x0);
  f1=F(x1);
  f2=F(x2);
  printf("\n%d %f %f %f %lf %lf %lf", i, x0,x1,x2,f0,f1,f2);
  if(f0*f2<0)
   {
    x1=x2;
   }
   else
   {
    x0=x2;
   }
   i++;
  }while(fabs(f2)>ESP);
printf("\n__________________________________________________________\n");
printf("\n\nApp.root = %f",x2);
getch();
}


//Output:
-------------
Enter the value of x0: 1

Enter the value of x1: 4