Re: cos() in math.h ?

[Kjetil Ødegaard <kjetilod@apollo.orakel.ntnu.no>]

* Christophe TROESTLER <ev_galois@freegates.be>
>
> 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 ?

You need to link with the math library; add -lm to your compiler command
line, ie.

gcc program.c -o program -lm

-- 
Kjetil