Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!zephyr.ens.tek.com!vice!bobb
From: bobb@vice.ICO.TEK.COM (Bob Beauchaine)
Newsgroups: comp.lang.pascal
Subject: Re: Needed:Trig Func arccos
Message-ID: <6335@vice.ICO.TEK.COM>
Date: 19 Nov 90 19:25:33 GMT
References: <7300@hub.ucsb.edu>
Distribution: comp
Organization: Tektronix Inc., Beaverton, Or.
Lines: 20

In article <7300@hub.ucsb.edu> 6600arac@ucsbuxa.ucsb.edu (Kenneth Mencher) writes:
>Okay peoples.  I'm working on a 3-d Rotation program
>that uses spherical co-ordinates.  Part of it
>involves using the arccos function.  Unfortunately,
>Turbo Pascal doesn't have one.
>
>I'd appreciate any help you can give me, from whole
>functions to hints.
>

  From _CRC_Standard_Mathematical_Tables

  Arccos(x) = PI/2 - Arctan(x /sqrt(1 - x*x))

  Arcsin(x) = Arctan(x/sqrt(1-x*x))

  All angles returned are, of course, principle angles.

  Bob Beauchaine
  bobb@vice.ICO.TEK.COM