3. The equation for the luminosity function defined by Schechter is:
(a) For the faintest galaxies, L << L Show that in that case the Schechter function is a power law.
(b) Considering only this regime of the faint galaxies, compute the total luminosity emitted by galaxies between luminosities Lmin and Lmax. Compute this for values of of -1, -2 and -3. Discuss which galaxies dominate the luminosity in this regime for the different values of a.