Thread: Square Root Problem

In addition, requirement 4 seems to indicate that you might also need to display, how many iterations it took to reach the result (probably 15 in most cases, because I don't trust comparing doubles with ==), and/or comparison of the result with sqrt() result.

Loops (blocks) are usually closed using the } bracket. I actually thought you didn't notice you had left out a part

here's my complete code (untested, so you compile):

Code:

#include <iostream>
#include <cmath>

using namepace std;

int main (int argc, char **argv)
{
	char quit = 'N';	
  	double userinput, y, x, a, lasty;		//All of our variables
	
	while (toupper(quit) != 'Y')
	{
		cout << "Please enter a non-zero number *****:" << flush;
		cin >> userinput;		//Get the number to be square rooted
		
		if (userinput <= 0)		//Is it a nonvalid number?
		{
			cout << "The number you entered was invalid. Would you like to quit (y/n)?" << flush;
			cin >> quit;		//Does the user want to quit?
			continue;		//If he wants to quit, then quit. Else, continue.
		}
		a = userinput;
		x = a;
		
		/*********Square root loop*************/
		lasty = 0;			//Null out lasty
		for (int i = 0; i <= 15; i++)
 		{
			y = 0.5*(x+a/x);	//This is our actual formula
			x = y;
			if (y == lasty)
			{
				break;		//Our formula has reached its end prematurely (under 15 loops)
			}
			lasty = y
		}
		cout << "The square root is " << y << "." << endl;
		cout << "Would you now like to quit (y/n)?" << flush;
		cin >> quit;
	}
	cout << "Ending...." << endl;
}

I hope that helps you.

Hey.
Thank you so much.. that works and the loop is complete...
anon had a point... requirement 4 does say i need to give some information about how many loops it would have taken it to find the root... how could i do this... (print how many loops it took)

you've really helped me a lot and i appreciate it.