Domain of Sin[ArcSin[x]] ?

*To*: mathgroup at smc.vnet.net*Subject*: [mg39620] Domain of Sin[ArcSin[x]] ?*From*: mbuescher at hb.edu (Michael Buescher)*Date*: Wed, 26 Feb 2003 02:42:54 -0500 (EST)*Organization*: Hathaway Brown School*Sender*: owner-wri-mathgroup at wolfram.com

I want to demonstrate to my students that in the real number system, Sin[ArcSin[x]] is only defined on [-1,1] because that is the domain of ArcSin[x]. When I Plot the composition, however, I get Sin[ArcSin[x]] = x for all real numbers, not just on [-1,1]. I tried this both with and without the RealOnly package. Is there any way to ensure that Mathematica uses only real numbers in its calculations, so that Sin[ArcSin[x]] is undefined when ArcSin[x] is not a real number? Michael Buescher Hathaway Brown School

**Follow-Ups**:**Re: Domain of Sin[ArcSin[x]] ?***From:*Dr Bob <drbob@bigfoot.com>