#include<stdio.h>
#include<conio.h>
#include<math.h>
#define E 0.0001
float f(float t)
{
    return((exp(-t))-t);
}
float df(float t)
{
    return (-(exp(-t))-1);
}
void main()
{
    int ctr,ctr1,po,ctr3;
    float FX1=0.0,F_X=0.0;
    float R1,X0,temp;


    clrscr();


    printf("\nEnter the Root::");
    flushall();
    scanf("%f",&R1);

    X0=R1;

//Puting the value in f(x)

    FX1  = f(R1);

//Putting the value in f!(x)

    F_X  = df(R1);

    printf("\n==========================================================");
    printf("\nNO\tX0\tFX1\tF_X");
    printf("\n==========================================================");

    ctr3=0;
    do
    {
        F_X=FX1=0;

        F_X = df(X0);

        FX1 = f(X0);

        temp=X0;

        X0 = X0 - (FX1/F_X);

        printf("\n%d\t%.4f\t%.4f\t%.4f\n",ctr3+1,X0,FX1,F_X);
        ctr3++;

    }
    while((fabs(temp-X0))>=E);
    printf("\n%.4f",X0);


    getch();
}


/***********************************OUTPUT*********************************

Enter the Root::0.5

==========================================================
NO      X0      FX1     F_X
==========================================================
1       0.5663  0.1065  -1.6065

2       0.5671  0.0013  -1.5676

3       0.5671  0.0000  -1.5671

0.5671

/******************************************************************************/