Re: Simplify problems for checking easy equalities...

*To*: mathgroup at smc.vnet.net*Subject*: [mg53876] Re: [mg53856] Simplify problems for checking easy equalities...*From*: yehuda ben-shimol <benshimo at bgumail.bgu.ac.il>*Date*: Tue, 1 Feb 2005 04:08:28 -0500 (EST)*References*: <200501300818.DAA08843@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

You only need to add some assumptions to your expressions, since for some set of values the Log[] is not defined For example use FullSimplify[Log[x^n] - n*Log[x], Assumptions -> x > 0 && n > 0] and it will return 0 as expected yehuda On Sunday 30 January 2005 10:18, Cyrus Erik Eierud wrote: > Please Help! > > Thanks for all great answers I've already found here! > My problem is that I can not simplify what to me seems as a very > simple equality task. This is what I want Mathematica to return zero > for: > > in[1]:= FullSimplify[Log[x^n] - n*Log[x]] > > out[1]= -n Log[x] + Log[x^n]) > > I have used Simplify to check equalities, but the one above (and many > other equations similar to the one above) just don't simplify. Am I > doing anything wrong or does anyone know of a better way to check > equalities? > > Appreciate any help, > Cyrus Eierud, Student > cyruserik at tele2.se