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From: Alan_T._Cote.OSBU_South@xerox.com
Newsgroups: comp.lang.pascal
Subject: Re: Trigonometric function
Message-ID: <24915@adm.BRL.MIL>
Date: 1 Nov 90 20:33:46 GMT
Sender: news@adm.BRL.MIL
Lines: 11

"John R. Evans" <evansjr@marlin.nosc.mil> writes:

>I would like to use the "arccos" function---but it is
>not standard pascal.
>
>Is there a simple way to do this using standard pascal
>functions such as arctan,sin, or cos?

Yes.  Use the identity,

     arccos(x) = arctan( ( 1 - ( x * x ) ) / x )