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Antonio Vernucci, I0JX US call: K0JX
Beacons: 50.004 MHz & 70.088 MHz
Home page: http://www.qsl.net/i0jx
e-mail: k0jx {at} amsat {dot} org
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"Helmut Wabnig" hwabnig@ .- --- -. dotat ha scritto nel messaggio
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On Fri, 08 May 2009 20:59:35 +0200, Helmut Wabnig hwabnig@ .- --- -.
dotat wrote:

On Fri, 8 May 2009 18:36:08 +0200, "Antonio Vernucci"
wrote:

I think this message can be of interest for those using Excel for antenna
calculations.

Write in one cell: =(-A1^2 + 8) Note: the exponent of A1 is 2 (and not
2+8=10) because Excel performs squaring before summing

Write in another cell: =(8 - A1^2)

They look pretty much the same

But give A1 any non-zero value and see what happen.

73

Tony I0JX
Rome, Italy

In correct mathematical convention the expression
let A1 = 2 then

-A1^2 must yield

-A1^2 = -4

otherwise we would have to write
(-A1)^2 = 4

EXCEL does it the wrong way in example 1: =(-A1^2 + 8) = 12
and does it correctly in example 2 =(8 - A1^2) = 4.
But they are from Microsoft and they can do whatever they want.

w.
TYPO correction
and does it correctly in example 2: =(8 - A1^2) = 4.