[cfp-interest 3505] Re: hypot(x, y) - C2Y F.10.5.4

[Vincent Lefevre]

On 2025-06-05 16:13:39 +1000, Damian McGuckin wrote:
> 
> In the latest draft,  the first item of paragraph 1 says
> 
> 	hypot (x, y), hypot (y, x), and hypot (x, -y) are equivalent.
> 
> Is that complete?

I think so.

> If +/- is my poor attempt at an plus-or-minus-sign, is this more thorough:
> 
> 	hypot(+/- x, +/- y) = hypot(|x|, |y|) = hypot(|y|, |x|)

The "=" is correct only when the result is not a NaN.

BTW, "hypot(+/-inf, y) returns +inf, even if y is a NaN" should
be "[...] even if y is a quiet NaN".

Similarly, in F.10.5.5 about pow, "for any {y,x}, even a NaN"
should be "[...], even a quiet NaN". Or like F.10.5.6 (pown):
"for all {y,x} not a signaling NaN".

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