Newton's Method Example

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

#define PI 3.14159265


double fonk(double x){

double retvalue;

retvalue=2*x-(x*sin(x))-0.5;
//printf("\n fonkvalue%lf",retvalue);

return retvalue;

}

double derivat(double x){

double retvalue=2-(sin(x)+x*cos(x));
return retvalue;



}

double erro(double old, double nev){
  double eror= ((nev-old)/nev)*100;
if(eror > 0){
// printf("%lf",eror);
return eror;
}else{
// printf("-%lf",eror);

return -1*eror;
}
}





int main(){

int i=1;
double array[25];
double error[25];
double guess,guessnew;
double tolarance;
printf("enter your guess;");
scanf("%lf",&guess);
    printf("enter your tolarance;");
scanf("%lf",&tolarance);
    array[0]=guess;  
   array[1]=guess-(fonk(guess)/derivat(guess));

   while(i<25){

   array[i+1]=array[i]-(fonk(array[i])/derivat(array[i]));   //yeni degerimiz:


if((array[1]-array[0])>0){          /////////////// ilk error değeri:
error[0]=((array[1]-array[0])/array[1])*100;
}else{
  error[0]=((array[1]-array[0])/array[1])*-100;
}







  error[i]=erro(array[i-1],array[i]);
   
    if(error[i]<tolarance){
   
 
    break;
   }
 
 
 

   i++;
   }
   
printf("itaretaed number:%d\t\troot:%lf",i,array[i]);

//printf("\n%lf\n",error[0]);
//printf("%lf\n",array[1]);

int j=0;
printf("\nerror:\t\t\troots:\n");
while(j<=i){

printf("%lf\t\t%lf\n",error[j],array[j]);



j++;




}














}