Help with understanding what his algorithm does and how it comes up with the numbers

Just starting to lean about algorithm and programming and professor gave us this question and told us to figure out what i does thanks for the help

Code:

---

#include <cstdlib>
#include <iostream>
#include <cmath>
using namespace std;
int main( )
{
  double a, x_old, x_new;
  cout << "Enter a positive DECIMAL number => ";
  cin >> a;
  x_old = 1;
  x_new = 0.5*( 1 + a );
  while( fabs(x_old - x_new) >= 0.00005)
  {
    x_old = x_new;
    x_new = 0.5*( x_old * x_old + a )/x_old;
  }
  cout << "\nThe value that you are seeking is " << x_new << endl;
  cout << "Press the enter key to continue ...";
  cin.get();
  return 0;
}

---

Quote:

---

Originally Posted by soldatik21

Just starting to lean about algorithm and programming and professor gave us this question and told us to figure out what i does thanks for the help

---

OK, so what's your question?

Regards,

Paul McKenzie

Quote:

---

Originally Posted by soldatik21

Just starting to lean about algorithm and programming and professor gave us this question and told us to figure out what i does thanks for the help

---

Then you should probably do what your professor asked you to do. This isn't the do my homework for me forum.

Take a look at this FAQ: http://forums.codeguru.com/showthrea...ork-assignment.

As a first step, ignore the actual code and just try running it. See what output you get for various input values. Then, try to guess what function the code is calculating (it should be fairly obvious).
Once you have an idea as to what function this code calculates, see if you can work out how it is doing it.