Consider a cavity of volume v filled with photons (a) show that the logarithm of photon's grand partition function q is (b) show that the equation of state of the photon gas can be specified by where 3 (c) determine the average number of photons (n) in the cavity and show that the mean energy per photon is approximately the following information may be (x) = with the riemann zeta-function ((v)2n. here are some frequently used values: (2) = π2/6, ζ(3) 1.202, e(4) = π4/90