PDES: GENERAL AND PARTICULAR SOLUTIONS
20.23 (a) Parabolic, open, Dirichletu(x,0) given, Neumann∂u/∂x=0atx=±L/ 2
for allt;
(b) elliptic, closed, Dirichlet;
(c) elliptic, closed, Neumann∂u/∂n=σ/ 0 ;
(d) hyperbolic, open, Cauchy.
20.25 Follow an argument similar to that in section 20.7 and argue that the additional
term
∫
m^2 |w|^2 dVmust be zero, and hence thatw= 0 everywhere.