6. For photons in equilibrium at temperature Tin a cavity of volume V Eq. (7.22) gives the energy density of photons with angular frequency in the range ω to ω + do. Show that the energy density of photons with wavelength in the range λ to λ + dÀIs given (a) dh. Explicitly show the value of A in your result. [4 marks] (b) Show that at temperature T. the maximum intensity occurs at wavelength /w , where and find the value of the constant b. [4 marks]