Thread: Square root function compiles but doesn't work

I am writing a program to find the square root of a number. I am using the Newton-Raphson method..Just to clarify a bit of the code.. fabs(1/(x+1)) < 0.001 is to check for relative error..

EXAMPLE: for user entry of 100 if the iteration process ends in 10.055 the answer will return as 10 which is correct. But it isn't doing that.

It compiles I then proceed to run it..prompts me "Enter a number to find the square root of: I type 100 then hit enter...

"The square root of 100 is -1077834936"

Lol could you give me a bit of guidance here..thanks. My first time writing a program from complete scratch.

And I know there is a sqrt() function...just wanted to write my own.

Thanks a lot

Code:

#include <stdio.h>
#include <math.h>
 
double mysqrt(double a);
 
int main()
{
 double a, result;
 
 printf("Enter a number to find the square root of: ");
 scanf("%d", &a);
 
 result = mysqrt(a);
 
 printf("The square root of %d is %d \n", a, result);
 
return 0;
}
double mysqrt(double a)
{
 double x, new_x;
 
 for(x=2; x != a;)
 {
   new_x=(x+1);
   new_x=(0.5*(x+(a/x)));
   x=new_x;
 
   if(fabs(1/(x+1))<0.001)
   {
    return new_x;
   }
 }
}