Where is sqrt, ceil and floor?

[Roberto Orenstein]

Hi list,

When compiling a program using a OpenGl lib, I got undefined references 
to sqrt, ceil an floor, as exposed bellow:

/usr/lib/libGLU.so: undefined reference to `sqrt'
/usr/lib/libGLU.so: undefined reference to `ceil'
/usr/lib/libGLU.so: undefined reference to `floor'
collect2: ld returned 1 exit status

After that I tried a simple program that just calls sqrt, and again got:
/tmp/ccQug9sn.o: In function `main':
/tmp/ccQug9sn.o(.text+0x26): undefined reference to `sqrt'
collect2: ld returned 1 exit status

These functions should be in glibc, right?
It seems that they aren't.

My system is a Linux system, the glibc is the standart that came with 
the distro and I didn't touch it or installed a new one.
glibc is 2.1.3

thanks for any help.

p.s -  please cc any reply to me, as I'm not subscribed to the list