Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2012

[Date Index] [Thread Index] [Author Index]

Search the Archive

Mathematica strange behaviour finding a cubic root

  • To: mathgroup at smc.vnet.net
  • Subject: [mg129111] Mathematica strange behaviour finding a cubic root
  • From: sergio_r at mail.com
  • Date: Sun, 16 Dec 2012 01:06:45 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • Delivered-to: l-mathgroup@wolfram.com
  • Delivered-to: mathgroup-newout@smc.vnet.net
  • Delivered-to: mathgroup-newsend@smc.vnet.net

How can I make Mathematica provides the same answer for
(-1/2)^(2/3) = ((-1/2)^2)^(1/3) ?

What follows is a Mathematica session:

In[1]:= (-1/2)^(2/3)

           1  2/3
Out[1]= (-(-))
           2

In[2]:= N[%]

Out[2]= -0.31498 + 0.545562 I

In[3]:= ((-1/2)^2)^(1/3)

         -(2/3)
Out[3]= 2

In[4]:= N[%]

Out[4]= 0.629961


Sergio



  • Prev by Date: Re: Clustering algorithm Mathematica 7
  • Next by Date: Ask for help to evaluate an equation
  • Previous by thread: Re: Clustering algorithm Mathematica 7
  • Next by thread: Re: Mathematica strange behaviour finding a cubic root