RE: capacitance of horned toroid

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "David Thomson" <dave-at-volantis-dot-org> 

Hi Godfrey,

 > Maybe you don't know Mathematica notation. (-1)^(n+1) means
 > -1 raised to the n+1 power.
 >
 > So (-1)^(1+1) = (-1)^(2) = (-1)(-1) = 1 and
 >
 >     (-1)^(2+1) = (-1)^(3) = (-1)(-1)(-1) = -1.

Thanks for working this out.  I do understand the notation as it is the same
as MS Excel.  But I rarely do math in my head anymore and rely heavily on
the computer to do it for me.  It's not laziness, I just have too many other
interests to be concerned with practicing math when a computer will do it
without error (or so I thought.)  In this case, MathCAD is clearly wrong and
it must have a bug.

 > Thanks, but I don't think I need MathCad. I don't
 > know if it has built in capacity to calculate
 > the zeros of Bessel functions.

Just FYI, here are the Bessel functions MathCAD does in the 2000 Pro
edition.  The newer edition might handle even more Bessel functions.  I'll
find out in a couple weeks when my 11.2 upgrade comes.

Bessel functions
J0(x)
J1(x)
Jn(m,x)
Y0(x)
Y1(x)
Yn(m,x)

Modified Bessel functions
I0(x)

I don't know if this tells you anything or not as I don't understand Bessel
functions, yet.

The reason I'm interested in your work is the equation you ended up with.  I
can understand it and it is similar in some respects to the equations on
subatomic particle spin I've been working on.

Dave