3. Green's functions (Haberman § 9.3, see problems 9.3.9 and 9.3.11) Consider d'u dr²+u = f(x) subject to subject to u(0) = 0, u(x/2) = 0. (14) The goal in (a)

is to find an integral representation for the unknown u(r) of the form u(x) = ™² G(E,x)ƒ (E)d£ (15) where G(r, ) is the Green's function. Note that (15) only holds for homogeneous boundary conditions (e.g. (14)). (a) Solve for G(§, z) directly from JG (§, x) მ2 (13) +G(§, x) = 8(§ - x) (16) G(0,r)=0 G(T/2, x) = 0. (17) You will need to determine and apply the matching conditions at = r as discussed in lecture to find G(z, E) (see also Haberman page 388).