atan2 - what and why?

From: Ken Quirici <kquirici_at_yahoo.com>
Date: Tue, 13 May 2014 11:25:11 -0700 (PDT)
Message-ID: <86b20948-ae74-4526-99f9-3038d1dc9f7e_at_googlegroups.com>

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? Received on Tue May 13 2014 - 20:25:11 CEST