HW5, given 10/28/99

1. equivalence of 
  (a) existence of fundamental solution for heat eq in U
  (b) existence of solution for heat eq with source term.
2. Heat dipole, show that lim v(x,t) = 0 as t \to 0. pointwise in x.
   show v(x,0) = delta'(x)
3. 3d wave equation using Fourier trandform, check the support.
4 #3 in Goodman 7.
5.#6 in p92, John.