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Old May 9th 09, 07:53 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default Be careful when using Excel

"Antonio Vernucci" wrote in
:

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)


Do you realise that the '-' in both expressions are quite different in
meaning, one is a unary negation operator, the other is the binary
subract operator.

No magic there, force the - to be a unary operator, and it behaves
consistently, eg 8+-2^2 gives 12.



They look pretty much the same


Not to a programmer!

Owen

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

73

Tony I0JX
Rome, Italy