Re: Re: question related to (-1)^(1/3)

*To*: mathgroup at smc.vnet.net*Subject*: [mg96766] Re: [mg96749] Re: question related to (-1)^(1/3)*From*: patapon <lxguard-hw at yahoo.com.cn>*Date*: Tue, 24 Feb 2009 05:46:25 -0500 (EST)*References*: <gnqo3c$c95$1@smc.vnet.net> <200902231004.FAA28251@smc.vnet.net>

I just want to get the real solution of (-1)^(1/3). BTW, I have read the tutorial but I am still confused with its explanation. But that is not important, I just feel it is inconvenient for the following problem: RecurrenceTable[{x[n + 1] == -x[n]^(1/3), x[0] == 1}, x, {n, 1, 200}] // N I consider there should be a way to limit the output in the domain real. for example, in MAXIMA (%i1) domain; (%o1) real (%i2) (-1)^(1/3); (%o2) -1 (%i3) domain:complex; (%o3) complex (%i4) (-1)^(1/3),numer; (%o4) 0.86602540378444*%i+0.5 On Mon, Feb 23, 2009 at 6:04 PM, Sjoerd C. de Vries < sjoerd.c.devries at gmail.com> wrote: > This misunderstanding pops up over and over again in this group. > Please type tutorial/FunctionsThatDoNotHaveUniqueValues in the search > bar of the mathematica doc centre. > > Cheers -- Sjoerd > > On Feb 22, 7:33 am, "=D2=BB=D2=B6=D6=AA=C7=EF" <lxguard... at yahoo.com.cn> = > wrote: > > I have tried expression: > > RecurrenceTable[{x[n + 1] == -x[n]^(1/3), x[0] == 1}, > > x, {n, 1, 200}] // N > > > > Mathematica produce > > {-1., -0.5 - 0.866025 I, -0.766044 + 0.642788 I, -0.686242 - > > 0.727374 I, -0.71393 + 0.700217 I, -0.704818 - 0.709389 I, > > ... > > > > But it should be {1, -1, 1, -1, ... } > > > > If you try (-1)^(1/3) > > > > In[10]:= (-1)^(1/3) > > > > Out[10]= (-1)^(1/3) > > > > In[11]:= % // N > > > > Out[11]= 0.5 + 0.866025 I > > >

**Follow-Ups**:**Re: Re: Re: question related to (-1)^(1/3)***From:*Murray Eisenberg <murray@math.umass.edu>

**References**:**Re: question related to (-1)^(1/3)***From:*"Sjoerd C. de Vries" <sjoerd.c.devries@gmail.com>