On 03-Aug-2000 Christophe TROESTLER wrote: > Hi all, > > According to the man page, if I want to use `cos' in a program, I > simply need to include `math.h'. However, when I compile, I got the > error: > > /tmp/cc9WOsLC.o(.text+0x16): undefined reference to `cos' > collect2: ld returned 1 exit status > > I got the necessary packages to compile (e.g., libc6-dev). Any idea > what is the cause ? >
when you use something from math.h you have to link with libmath, using -lm on the command line: gcc foo.c -lm -o foo
