simple sqrt function doesn't work!

the following very basic code is not compiling in Dynix.
It says undefind symbol sqrt first referenced in file souce.o

/* file source.c */
#include<stdio.h>
#include<math.h>

void main(void)
{
double i;
i=sqrt(25.00);
printf("value is = %i\n",i);
}
/* end of code*/

Where is the problem? Why sqrt doesn't work even if I included math.h?

I don't know dynix - but - most unix command line compilers require that you tell them to link in the mathlib something like this

cc -lm myfile.c

try: man cc


for specific information for your compiler on how to link the math library.

Also - most man pages have the information you need by typing:

man math