import java.io.*;
public class sqrt
{
   public static void main(String[] argv)
   {
      double x, sqrt, epsilon;

      x = 3;
      epsilon = 0.005; 
      System.out.println(" square root of " + x + " is " +
                         squareRoot(x,epsilon));
   }
 
   // find square root of x with the given precision
   private static double squareRoot(double x, double epsilon)
   {
      double y;
      y = x;
      while (!closeEnough(x, y*y, epsilon))
         y = (y + x / y) / 2.0;
      return y;
   } // squareRoot

   // compare the tolerance
   private static boolean closeEnough(double a, double b, double eps)
   {
      return Math.abs(a - b) < eps;
   } // closeEnough
}