On Thu, 4 Nov 2004 at 18:23:24 in message
. com, Raul Ruiz
wrote:
Divide by zero error! A division by zero is undefined, so I think
John's statement is correct. Even if you take the limit as the
effective speed goes to zero, the result is infinity, which is also,
theoretically, an undefineable number since it leads to inherent
contradictions in the strict sense. If we were to take ANM as a strict
mathematical concept, then I fear we would be laughed at. But
practically speaking, you're never going to have an effective ground
speed of 0 in an airplane.

That does not answer the fact that the original statement by John
appears to me to be wrong.

What is wrong with my calculations? I am perfectly willing to hear
corrections or that I was wrong.

A divide by zero error is a *computing* error that computers cannot
easily handle. There is nothing mathematically wrong with a result of
infinity.

In this case it merely represents the obvious fact that if you head into
a wind of the same strength as your cruising speed you will not get
anywhere. There is no contradiction in a result of infinity per se. Some
practical problems break down at that point. This one doesn't. The
meaning of infinity in this case is perfectly clear.

Finally a division of a real number by zero is *not* undefined, the
answer is unequivocally infinity. Zero divided by zero is undefined.

I await John's response.
--
David CL Francis