Re: Simplifying Sqrt[a^2*d^2]
- To: mathgroup at smc.vnet.net
- Subject: [mg8441] Re: Simplifying Sqrt[a^2*d^2]
- From: Ersek_Ted%PAX1A at mr.nawcad.navy.mil
- Date: Sat, 30 Aug 1997 00:42:51 -0400
- Sender: owner-wri-mathgroup at wolfram.com
>Carlos A. Felippa wrote:
>
> I want Sqrt[a^2*d^2] to be automatically simplified to a*d
> wherever it appears in a very complex expression.
>
> In another system I simply declare a and d real nonnegative and let the
> program figure out the rest. How do I do that in Mathematica?
> The obvious rule expr/.{Sqrt[a^2*d^2]->a*d} does not work.
>
Use the following.
In[1]:= PowerExpand[ Sqrt[a^2 d^2] ]
Out[2]= a d
Of course this may not be true if "a" or "d" are Complex.
WRI discusses simplification problems like this at:
http://www.wolfram.com/support/Math/Algebra/ConditionalSimplification/html
Ted Ersek