/* Newton -Raphson method*/
#include<math.h>
#include<stdio.h>
float f(float x)
{
float f;
f=x+log(x)-2;
return(f);
}
float df(float x)
{
float df;
df=(1+1/x);
return (df);
}
// #define df(x) (x*cos(x))
main()
{
float x[50],e,a,b;
int k;
printf("\n Enter accuracy e=");
scanf("%f",&e);
do
{
printf("\n Enter interval a,b ");
scanf("%f%f",&a,&b);
}while(f(a)*f(b)>0.0);
x[0]=(fabs(f(a))>fabs(f(b))?b:a);
printf("%f",x[0]);
k=0;
do
{
x[k+1]=x[k]-(f(x[k])/(df(x[k])));
printf("\nk=%d x[k]=%f ",k,x[k]);
k=k+1;
}
while(fabs(x[k]-x[k-1])>=e && k<=20);
printf("\n\n Root of the Equation is %f\n\n",x[k]);
printf("\n No. of iterations =%d",k);
getch();
}