Re: atan2 - what and why?
From: ddf <oratune_at_msn.com>
Date: Tue, 13 May 2014 12:15:54 -0700 (PDT)
Message-ID: <def5ea8d-fd6e-4501-919f-92ba6a7f58a7_at_googlegroups.com>
On Tuesday, May 13, 2014 12:25:11 PM UTC-6, Ken Quirici wrote:
> The documentation on this, and google search results, are strange. atan is arctan - that is, the angle whose tangent is its single argument.
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> AFA atan2:
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> There is only an atan2, no asin2 or acos2.
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> The doc for 11g and 12c says atan2(a1, a2) is the atan of a1 and a2. This is obscure at best.
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> Other documentation says it's the atan of a1/a2. Oh, so that's it.
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> Is there some special reason for this to exist at all, and if so, does this reason cover the fact that
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> asin2 and acos2 don't exist?
Date: Tue, 13 May 2014 12:15:54 -0700 (PDT)
Message-ID: <def5ea8d-fd6e-4501-919f-92ba6a7f58a7_at_googlegroups.com>
On Tuesday, May 13, 2014 12:25:11 PM UTC-6, Ken Quirici wrote:
> The documentation on this, and google search results, are strange. atan is arctan - that is, the angle whose tangent is its single argument.
>
>
>
> AFA atan2:
>
>
>
> There is only an atan2, no asin2 or acos2.
>
>
>
> The doc for 11g and 12c says atan2(a1, a2) is the atan of a1 and a2. This is obscure at best.
>
>
>
> Other documentation says it's the atan of a1/a2. Oh, so that's it.
>
>
>
> Is there some special reason for this to exist at all, and if so, does this reason cover the fact that
>
> asin2 and acos2 don't exist?
Read here:
http://en.wikipedia.org/wiki/Inverse_trigonometric_functions
Arctan is the only one of the three arc functions you mentioned that has a two argument variant.
David Fitzjarrell Received on Tue May 13 2014 - 21:15:54 CEST