Nm

Search through an archive for a particular symbol
Executing the following example:

nm -A /usr/lib/nptl/libpthread.a | grep pthread_mutex_lock

Will give something like the following information:

/usr/lib/nptl/libpthread.a:pthread_mutex_lock.o:        U __lll_lock_wait /usr/lib/nptl/libpthread.a:pthread_mutex_lock.o:00000000 T __pthread_mutex_lock /usr/lib/nptl/libpthread.a:pthread_mutex_lock.o:00000000 T pthread_mutex_lock /usr/lib/nptl/libpthread.a:pthread_mutex_lock.o:00000000 T __pthread_mutex_lock_internal