#include "config.h"

double positive (double x) {

  if (x > 0.0) 
    return x;
  else 
    return 0.0 - x;

}

double sqrt (double a) {

  double x_old = 1.0, x_new = 0.5;

  if (a > 0.0) {
    do {

      x_old = x_new;
      x_new = ((a / x_old) + x_old) / 2.0;

    } while (positive(x_old - x_new) > MY_DELTA_MAX);

    return x_new;

  } else exit(1);

}