Cube root of -1 and 1

*To*: mathgroup at smc.vnet.net*Subject*: [mg90875] Cube root of -1 and 1*From*: Bob F <deepyogurt at gmail.com>*Date*: Sun, 27 Jul 2008 02:32:16 -0400 (EDT)

Could someone explain why Mathematica evaluates these so differently? In[53]:= (Sqrt[36] - 7)^(1/3) (Sqrt[36] - 5)^(1/3) Out[53]= (-1)^(1/3) Out[54]= 1 In other words why isn't (-1)^1/3 expressed as -1 ?? Thanks... -Bob

**Follow-Ups**:**Re: Cube root of -1 and 1***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>

**Re: Cube root of -1 and 1***From:*Murray Eisenberg <murray@math.umass.edu>