2. A solid sphere r 0), where go is a positive constant. Make the substitution W". t) = U (r, I) + (130') in the temperature problem for this sphere, where U and (I) are to be continuous when r = 0. [Note that this continuity condition implies that r(r) tends to zero as r tends to zero] Then refer to the solution derived in Example 1, Sec. 41, to write the solution of a new boundary value problem for U (r, I) and thus show that 1 2 1 " uh", I) = 3: 5:11 r2) + E Z ( n3) e'"2\"2"' sinmrr . \"=1 Suggestion: It is useful to note that in view of the formula for the coefcients in a Fourier sine series, the values of certain integrals that arise are, except for a constant factor, the coefcients in the following series [see Problem 4(a), Sec. 8]: 00 12 (-1)\"+1 . 2 r(1r)=; gun331nm?!\" (0