To prove (∂U/∂V)P = TCV/V for a perfect gas, begin with the internal energy equation, U, expressed in terms of temperature and volume. The discussion suggests using the differential form dU = CvdT, which relates changes in internal energy to temperature changes at constant volume. Expanding U in terms of temperature and volume will clarify the relationship, leading to the desired equation. It is emphasized to remember that this involves a partial derivative and to conclude with QED. This approach provides a structured method to derive the required proof.