Re: Why is this so?
- To: mathgroup at smc.vnet.net
- Subject: [mg15342] Re: Why is this so?
- From: "Atsushi ODA" <a-oda at muj.biglobe.ne.jp>
- Date: Fri, 8 Jan 1999 04:15:29 -0500
- Organization: BIGLOBE dial-up user
- References: <76pq9g$e0n@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Chester Lin wrote in message <76pq9g$e0n at smc.vnet.net>... >Isn't it true that (-125)^(1/3) == -5? > >Why do I get this strange result? > >I am using Mathematica 3.01 for Students on Macintosh. > >Thanks for any info. > >Chester Lin >chester at nicco.sscnet.ucla.edu > Usually, Mathematica treated every number as complex. So in your case, you have three values for (-125)^(1/3) such as -5*(1/2+Sqrt[3]/2 I),-5*(1/2-Sqrt[3]/2 I) and -5. That's why mathematica tell "not a machine-size *real* number". Solution is easy. Just load standard package, "Miscellaneous`RealOnly` ". You should consult standard package manual, then you will find exactly same example of yours. Atsushi ODA <a-oda at muj.biglobe.ne.jp> Kawasaki, JAPAN