Date:	Thu, 5 Jul 2001 09:44:18 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To:	djgpp AT delorie DOT com
Subject:	Re: DJGPP reserves wrong int size
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On Wed, 4 Jul 2001, Graaagh the Mighty wrote:

> >In any decent course in numerical computation, the first lesson
> >teaches you that you cannot even solve a quadratic equation without
> >risking numerical pitfalls.
> 
> Newton's method? That does division, iteratively. The quadratic
> formula? I doubt you'll have trouble with numerical instability except
> right on the threshold of zero.

It's enough to have two solutions close to one another to get into
trouble, because the formula for solving the quadratic subtracts two
numbers under the square root, and one of them is squared, so it loses
half of its significant digits.

> Now please stop spouting your "numerical wisdom" and give some real,
> usable information about what might cause what was observed

I did give usable information.  If you don't want to hear any advice
you don't like, don't post questions.

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