5. For a central potential V (r), we can take our energy eigenstates to be products of the form XIJ(r, 0, q_b) m (0, qb) for some C, m. Recall that if we define u(r) rR(r), then u satisfies the radial equation h2 (1271 2m dr2 '2mr2 where E is the energy of W. Using the variational principle, show that the ground state always has C Hint: Consider as your set of trial wavefunctions the (0, c/)) themselves. o.