Re: how can I return nothing?

In article <ln8x72jaxs.fsf@xxxxxxxxxxxxxxx>,
Keith Thompson <kst-u@xxxxxxx> wrote:

(You do have a point though: there is no way to distinguish between
i and -i.)

Um, -i is the one with the minus sign in front of it.

:-)

Seriously, I'm not sure what you mean by "no way to distinguish". For
positive operands, only the positive square root is considered to be
*the* square root (e.g., sqrt(4.0) is 2.0, not -2.0). Similar rules
apply for negative and even complex operands.

Right, but which square root of -1 is the positive one?

Imagine you're talking to an alien, and you want to describe the
square roots of 4. There are two of them, and one of them happens to
have the property that when you add it to itself, you get four again.
So you can easily specify which one you're talking about (and of
course you can do it in lots of other ways).

Now you want to describe the square roots of -1. There are two of
them, but which is the one you call i? Suppose he calls the square
root of -1 j: is j the same as i or is it -i? There's no way to tell.

-- Richard
--
"Consideration shall be given to the need for as many as 32 characters
in some alphabets" - X3.4, 1963.
.

Relevant Pages

  • Re: how can I return nothing?
    ... positive operands, only the positive square root is considered to be ... but which square root of -1 is the positive one? ... Imagine you're talking to an alien, and you want to describe the ... So you're saying that if you took the complex plane (the set of all ...
    (comp.lang.c)
  • Re: how can I return nothing?
    ... positive operands, only the positive square root is considered to be ... apply for negative and even complex operands. ... but which square root of -1 is the positive one? ... Not the other way round. ...
    (comp.lang.c)