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Re: Which calculator to use for "arctan(tan(269))"?
From: Stan K
Date: 2016 Nov 3, 19:12 -0400
From: Stan K
Date: 2016 Nov 3, 19:12 -0400
Tony,
I'm pretty sure all calculators reduce inverse trig functions to minimal ranges. Arcsin -90º to +90º, arccos 0º to 180º, arctan -90º to +90º, etc.
Stan
-----Original Message-----
From: Tony Oz <NoReply_TonyOz@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, 3 Nov 2016 18:49
Subject: [NavList] Which calculator to use for "arctan(tan(269))"?
From: Tony Oz <NoReply_TonyOz@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Thu, 3 Nov 2016 18:49
Subject: [NavList] Which calculator to use for "arctan(tan(269))"?
My Casio fx-85ES Plus gives me tan-1(tan(269))=89, which is an unpleasant surprise for me.
Because of that the formula
Zc = tan-1{ [ cos(Dec) · sin(GHA+LonAP) ] / [ cos(LatAP) · sin(Dec) - sin(LatAP) · cos(Dec) · cos(GHA+LonAP) ] }
on my fx-85ES has 180° ambiguity.
Is there a more smart calculator that could handle all the -180°..+180° range for reverse trig functions?
Thank you in advance.
Regards,
Tony
