Edit: LOTS OF TYPOS (sorry guys)(adsbygoogle = window.adsbygoogle || []).push({});

Let:

[tex] f(r) = e^{-(a-r)^2} [/tex]

[tex] g(r) = r e^{-(a-r)^2} [/tex]

Where a is some constant

Can:

[tex]

\dfrac{ \sum\limits^{r=\infty}_{r=-\infty} g(r) } {\sum\limits^{r=\infty}_{r=-\infty} f(r) }

[/tex]

Be simplified?

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# Nasty summation + derivative help

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