#include <math.h>
#include <stdio.h>
int main()
{
double x = 0;
double y = 0;
double y_1;
long i;
while(1)
{
printf("Enter x : ");
if(!scanf("%lf",&x) || getchar() != '\n')
{
while(getchar() != '\n'){}
printf("bad input\n");
}
else
{
if((y_1 = x) != 0)
{
i = 0;
do
{
y = y_1;
y_1 = y + (y - pow(y,4.0)/x)/3;
printf("Iteration %d\n", (i = i + 1));
printf("y = %lf\t error = %lf\n", y_1, fabs(y_1 - y));
}
while(2*pow(10.0,-6.0) < fabs(y_1 - y));
}
printf("answer : %lf\n",y_1);
}
}
return 0;
}