(a) Linearize the Stefan--Boltzmann equation in the form of Eq. (3.17) to show that
L0δL=2R0δR+4T0δT.(b) Linearize the adiabatic relation TVγ−1=constant, and so find a relation between δL/L0 and δR/R0 for a spherical blackbody model star composed of an ideal monatomic gas.