  The mode frequencies of a weakly interacting Bose gas in a magnetic trap are
studied as a function of the anisotropy of the trap. As in earlier works the
generalized Hartree-Fock-Bogoliubov equations within the Popov approximation
(HFB-Popov) are used for our calculations. The new feature of our work is the
combined use of a mode expansion in a finite basis and a semiclassical
approximation of the highly excited states. The results are applied to check
the accuracy of the recently suggested equivalent zero-temperature condensate
(EZC) approximation which involves a much simpler model.
