class Ex1_2_6 {
  public static void main(String[] args) {
    double un, u0, a;
    double eps = 1e-8;

    a = 2.0;

    u0 = a;
    un = 0.5 * (u0 + a / u0);

    while (Math.abs(un - u0) >= eps) {
      u0 = un;
      un = 0.5 * (u0 + a / u0);
    }

    System.out.println("La racine carré de " + a + " est " + un);
  }
}