  We present analytical formulae for the first and second derivatives of the
Helmholtz free energy of non-relativistic ideal Fermi-gas. Important
thermodynamic quantities such as heat capacity, sound velocity, heat capacity
ratio and others can be easily expressed through the derivatives. We
demonstrate correct ideal Boltzmann gas and low--temperature Fermi-gas
asymptotes and derive corrections to thermodynamic functions for these limiting
cases. Numerical computations of thermodynamic properties of ideal Fermi-gas
can be accurately performed using the developed freely available Python module
ifg.
