http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56946
--- Comment #3 from shia <zhabgyuan1993 at gmail dot com> 2013-04-13 14:13:08 UTC --- (In reply to comment #2) > You need to add -lm to your command line. gcc -lm -Wall assignment.c This is right?But it can't compile neither