Hey, I am new to both these forums and C in general, so I might be overlooking something simple. If that's the case, sorry, but Google searches got me nothing. Here's the problem:

I am going to Project Euler's problems, and am hitting a wall with both Project 7 and Project 3. Both of those involve deciding whether a number is a prime, which I have implemented with an additional function that looks like this:

There may be a more efficient way to implement this, but I think this should work. I have #included <math.h> as well. Here is how the rest of my ideas fit into this:Code:/* Prime Number Checker * Takes an integer as an argument * Returns 1 if the integer is prime * Returns 0 if the integer is composite */ int is_prime(int n) { int i; for (i = 2; i < sqrt(n); i++) { if ( n%i == 0 && n > 3) { return 0; } } return 1; }

I have a 003.c (007.c too, but that's irrelevant for now) file in my .../003 folder, as well as a soft link functions.h to .../Functions/functions.h, where my is_prime function is. I've included <math.h> and "functions.h in the 003.c. Somehow functions.h compiles with no problems, but 003.c gives me the

There is a little more text to the warning, but I don't see how it could be helpful or relevant. I'll paste it if needed.Code:undefined reference to 'sqrt'

Any thoughts?