Re: Simplify problems for checking easy equalities...
- To: mathgroup at smc.vnet.net
- Subject: [mg53874] Re: Simplify problems for checking easy equalities...
- From: "Dr. Wolfgang Hintze" <weh at snafu.de>
- Date: Tue, 1 Feb 2005 04:08:25 -0500 (EST)
- References: <cti5nd$8n2$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Try to impose reasonable conditions on x and n:
In[22]:=
Simplify[Log[x^n] == n*Log[x], {x > 0, n \[Element] Reals}]
Out[22]=
True
or
In[23]:=
Simplify[Log[x^n] == n*Log[x], {x > 0, Im[n] == 0}]
Out[23]=
True
but it's not enough to just say x>0:
In[24]:=
Simplify[Log[x^n] == n*Log[x], x > 0]
Out[24]=
Log[x^n] == n*Log[x]
Hopre this hepls
Wolfgang
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
>
>