Newton raphson method

#include<stdio.h>

#include<math.h>

 

double f(double x){

  return x*x*x-8*x-4;

}

 

double df(double x){

  return 3*x*x-8;

}

 

double rootNR(double f(double x),double df(double x),double x1,double eps,double maxSteps){

  double x;

  int i=1;

  do{

    x=x1;

    if(fabs(df(x))>=0.000000001){

      x1=x-f(x)/df(x);

      i++;

    }

  }while(fabs(x-x1)>=eps&&i<=maxSteps);

  return x1;

}

 

double printNR(double f(double x),double df(double x),double x1,double eps,double maxSteps){

  double x;

  int iter=1;

  printf("___________________________________________________________________________________________________\n");

  printf("iter\tx\t\tf(x)\t\tf'(x)\t\tx1\t\t|x-x1|\t\tf(x1)\n");

  printf("___________________________________________________________________________________________________\n");

  do{

    x=x1;

    if(fabs(df(x))>=0.000000001){

      x1=x-f(x)/df(x);

      printf("%d.\t%lf\t%lf\t%lf\t%lf\t%lf\t%lf\n",iter,x,f(x),df(x),x1,fabs(x-x1),f(x1));

      iter++;

    }

  }while(fabs(x-x1)>=eps&&iter<=maxSteps);

  return x1;

}

main(){

  double x,eps,x1;

  int maxSteps;

  printf("Enter the initial guess:\n");

  scanf("%lf",&x);

  printf("Enter the accuracy:\n");

  scanf("%lf",&eps);

  printf("Enter the maximum no. of steps:\n");

  scanf("%d",&maxSteps);

  printf("__________________________________________________________________________________________________\n\n The roots of the given equation is:\n\n%lf\n\n\n",printNR(f,df,x,eps,maxSteps));

   

}