Toronto Math Forum
APM3462018S => APM346Lectures => Topic started by: Adam Gao on March 19, 2018, 06:18:38 PM

Why do we drop unbounded terms from solutions to PDE's? Specifically, in section 6.2, Laplace equation in halfstrip:
$$Y''= \lambda Y$$
yields solution
$$Y=Ae^{\sqrt{\lambda}y}+Be^{\sqrt{\lambda}y}$$
And then the second term is dropped because it is unbounded

We are looking for a bounded solution. You may consider this as "boundary condition at infinity"