Re: How to Multiply Sqrt[a] with Sqrt[b]
- To: mathgroup at smc.vnet.net
 - Subject: [mg38182] Re: [mg38134] How to Multiply Sqrt[a] with Sqrt[b]
 - From: Vladimir Bondarenko <vvb at mail.strace.net>
 - Date: Wed, 4 Dec 2002 03:26:12 -0500 (EST)
 - In-reply-to: <200212030934.EAA14825@smc.vnet.net>
 - References: <200212030934.EAA14825@smc.vnet.net>
 - Reply-to: Vladimir Bondarenko <vvb at mail.strace.net>
 - Sender: owner-wri-mathgroup at wolfram.com
 
"Gernot Pfanner" <pfannerg at kfunigraz.ac.at> wrote on Tuesday, December 03, 2002, 5:34:51 AM :
GP> Does somebody know an algorithm to simplify the product  Sqrt[a]*Sqrt[b] ?
Apply Simplify or FullSimplify with Assumptions.
Generally speaking, over the complex plane, Sqrt[a]*Sqrt[b] cannot be
simplified further, and Mathematica "knows" it.
  In[1] := FullSimplify[Sqrt[x]Sqrt[y], x \[Element] Complexes]
  Out[1] = Sqrt[x]*Sqrt[y]
The same holds for the real plane.
  In[2] := FullSimplify[Sqrt[x] Sqrt[y], x \[Element] Reals]
  Out[2] = Sqrt[x]*Sqrt[y]
Sometimes, if your work over the real plane, things might look simpler.
  In[3] := Simplify[Sqrt[x] Sqrt[y], x > 0 && y > 0]
  Out[3] = Sqrt[x*y]
  In[4] := Simplify[Sqrt[x] Sqrt[y], x < 0 && y < 0]
  Out[4] = -Sqrt[x*y]
and so on.
Best wishes,
Vladimir Bondarenko
Mathematical and Production Director
Symbolic Testing Group
        http://www.CAS-testing.org/  GEMM Project             (95% ready)
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- References:
- How to Multiply Sqrt[a] with Sqrt[b]
- From: "Gernot Pfanner" <pfannerg@kfunigraz.ac.at>
 
 
 - How to Multiply Sqrt[a] with Sqrt[b]