C program to find Square Root

In this post, I am going to write a very simple C program to find Square Root. I am using the Newton Raphson method to find the square root of a number.

#include <stdio.h>
#include <math.h>

// equivalent to 10^-7 -> accurate upto 7 decimal places
// can be set according to need or even taken in as input 
const double MAX_ERROR = 1e-7; 
							   
// Function to return the Square Root value
double squareRoot(int x)
{
	// initial guess for the root
	double r = 1; 
	while (fabs(r*r - x) > MAX_ERROR)
	{
		// value of 'r' moves closer and closer to the actual root value
		r = (r + x/r) / 2; 
	}

	return r;
}

int main()
{
	// get the number from user
	int num;
	printf("Enter a number to find the Sqaure root:");
	scanf("%d", &num);

	printf("%lf", squareRoot(num));

	return 0;
}

Sample output of this program:

Enter a number to find the Sqaure root:3
1.732051
--------------------------------
Process exited after 1.78 seconds with return value 0
Press any key to continue . . .