Re: NEC-LIST: Symbolic evaluation of integrals

dr/dx = x / sqrt(x2+c2);

D. B. Miron wrote:

> Happy New Year to you Malcolm,
>
> I assume you've looked in the big Russian compilation, by Gradsteyn and
> Ridzhykh, so I won't. I did look in Pierce and Foster's "A Short Table of
> Integbrals", 4th ed., for related forms. There's no help even in the
> definite integrals.
>
> It occurs to me that
> d(exp(-jkr))/dx = d((-jkr))/dr dr/dx
> =-jk exp(-jkr) dr/dx = -jk exp(-jkr) x/r = -jk d( I_a.)/dx
> so
> I_a=exp(-jkr)/(-jk).
>
> Am I missing something here?
>
> Doug Miron
>

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