[OCLUG-devel] math functions in C

[Thomas Moore]

Hi all,

I have only been on this list for a short time but
have never seen a posting. But I will anyway. I am
not a programmer but do write small programs for
my amusement.

Here is a short C program to illustrate my
problem:



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

int main(void)
{
	double x = .7854;
	double y;
	
	y = sin(x);
	printf("sin(%f) = %f\n\n", x, y);
}

Then doing

gcc -o prog prog.c

I get the following message:


/tmp/ccZW5o7k.o(.text+0x1a): In function `main':
: undefined reference to `sin'
collect2: ld returned 1 exit status


Now, math.h refers to mathcall.h which contains
all the function prototypes. Why will this not
compile? Or more to the point, what am I doing
wrong?

Thanks.

Tom