Finish either question 3 or 4 please

J () . 3. Consider d' G da2 +G =8(x - To) with G(0, To) - 0 and G(L, To) = 0, (a) Solve for this Green's function directly. Why is it necessary to assume that L # nn? (b) Show that G(r, To) = G(To, I). 4. Consider Lu] = f(x) with _ = _(p-) + q. Assume that the appropriate Green's function exists. Determine the representation of u(r) in terms of the Green's function if the boundary conditions are nonhomogeneous. (a) u(0) = a and u(L) = (b) "(0) = a and th (L) = B (c) u(0) = a and du (L) = B (d) u(0) = a and TH ( L) + hu( L) = B