Why is it alway said that "fabs" and "sqrt" are undefined symbol ?

Dear all,

HMETIS_PartRecursive() is needed in our C program.
However, when we link our program with libhmetis.a,
it's always said that

Undefined first referenced
symbol in file
fabs libhmetis.a(util.o)
sqrt libhmetis.a(GKlib.o)

Could anyone provide me some suggestions?
Thanks a lot.

Robin
atinrichard@hotmail.com