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Problem to evaluate cube root of a negative cube nember where a real value is expected

  • To: mathgroup at smc.vnet.net
  • Subject: [mg28042] Problem to evaluate cube root of a negative cube nember where a real value is expected
  • From: "Gary" <garylga at magix.com.sg>
  • Date: Thu, 29 Mar 2001 03:24:09 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

Hi,

Does anyone know a simplier way to simplify (-8)^(1/3)=(-2) other than what
I did below because no complex answer is expected in the solution.

In[161]:=
p=(-8)^(1/3)
q=Abs[p]
Level[p,3]
r=Extract[Level[p,3],2]
(* if p is real, then p should be as below *)
q*r

Out[161]=
\!\(2\ \((\(-1\))\)\^\(1/3\)\)

Out[162]=
2

Out[163]=
\!\({2, \(-1\), 1\/3, \((\(-1\))\)\^\(1/3\)}\)

Out[164]=
-1

Out[165]=
-2


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Gary Lee Guanan (garylga at magix.com.sg)
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