#include
#include
using namespace std;
//x(n + 1) = (xn+a/xn)/2
void NewtonSqrt(double a,double &x){
a = x - (x + a / x) / 2;
if (a<= 0.00001)
return;
x = (x + a / x) / 2;
NewtonSqrt(a, x);
}
void main(){
double a = 3;
double x = a / 2;
cout << x <<endl;
_getch();
}