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OliviaB
Oct18-10, 09:32 AM
I think this is Poisson's Equation (and inhomogenous). I think I need to use Green's Identity.

Let \mathcal{R} be a bounded region in \mathbb{R}^3, and suppose p(x) > 0 on \mathcal{R}.

(i) If u is a solution of

\bigtriangledown^2 u = p(x) u \ \ x \in \mathcal{R} \ \ \bigtriangledown \cdot n = 0 \ \x \in \partial \mathcal{R}

show that u \equiv 0 on \mathcal{R}

(ii) If u is a solution of

\bigtriangledown^2 u = p(x) u \ \ x \in \mathcal{R} \ \ \bigtriangledown \cdot n = g(x) \ \x \in \partial \mathcal{R}

show that u is unique (It can be assumed that part (i) is true).

I dont know how to start this...