RE: FullSimplify doesn't simplify
- To: mathgroup at smc.vnet.net
- Subject: [mg32772] RE: [mg32762] FullSimplify doesn't simplify
- From: "Florian Jaccard" <jaccardf at eicn.ch>
- Date: Sat, 9 Feb 2002 05:11:43 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hello Ken !
Yes, there are cases !
For exemple, (-1)^(1/2)*(-1)^(1/2)=-1
but ((-1)(-1))^(1/2)=1
It is not a Mathematica problem, but Mathematics !
Remember : (a*b)^n=(a^n)*(b^n) is always true only if a and b are real
positive numbers.
Indeed, Mathematica knows it :
In[1]:= Simplify[(a*b)^n==a^n*b^n,{a>0,b>0}]
Out[1]= True
Greetings
Florian Jaccard
EICN-HES
e-mail : jaccardf at eicn.ch
-----Message d'origine-----
De : Ken Morgan [mailto:kmorga51 at calvin.edu]
Envoyé : ven., 8. février 2002 09:50
À : mathgroup at smc.vnet.net
Objet : [mg32762] FullSimplify doesn't simplify
Does anyone know why Mathematica doesn't simplify the following to True?
In[1] := FullSimplify[(x y)^n == (x^n)(y^n)]
Out[1] := (x y)^n == (x^n)(y^n)
Are there cases where this is not true?
Thanks,
Ken Morgan
kmorga51 at calvin.edu