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- #1

- Jun 20, 2014

- 1,925

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Show that, for every compactly supported, smooth, real valued function $f : \Bbb R^3 \to \Bbb R$,

$$\iiint_{\Bbb R^3} \nabla^2\left(\frac{1}{\| \mathbf{x} - \mathbf{y}\|}\right) f(\mathbf{x})\, d\mathbf{x} = -4\pi f(\mathbf{y})$$

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