Bisection (c)

#include<stdio.h>
#include <math.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;

    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);

}