- #1

Logarythmic

- 281

- 0

[tex]\tilde{f} (x) = a_n|e_n>[/tex]

where

[tex]|e_n> = e^{2 \pi inx / L}[/tex]

and

[tex]a_n = \frac{1}{L}<e_n|f>[/tex]

for my Fourier expansions.

How do I expand a function in 3 dimensions, for example

[tex]V(\vec{r}) = \frac{e^{-\lambda r}}{r}[/tex]

?