牛頓法求算數平方根

package com.mercurylake.test.stack;

public class Sqrt {

static double sqrt_(double x)         

{

   double g=x;

   while(Math.abs(g*g-x)>0.000001)

   {

       g=(g+x/g)/2;

   }

   return g;

}

public static void main(String[] args) {

double x=sqrt_(4);

System.out.println((int)x);

}

}