Re: Equations over Domains with Mathematica 4?
- To: mathgroup at smc.vnet.net
- Subject: [mg103112] Re: Equations over Domains with Mathematica 4?
- From: Emu <samuel.thomas.blake at gmail.com>
- Date: Tue, 8 Sep 2009 05:59:00 -0400 (EDT)
- References: <h80705$18i$1@smc.vnet.net> <h829jq$3ri$1@smc.vnet.net>
On Sep 7, 4:35 pm, Emu <samuel.thomas.bl... at gmail.com> wrote:
> On Sep 6, 9:38=C2 pm, Martin Harborth <martin.harbo... at yahoo.de> wrote:
>
>
>
>
>
> > For the following equation, I want to get only the solutions
> > for z where z is real:
>
> > Reduce[13219.56 == 20000/1.95583 * (1 + z)^11, z]
>
> > It is suggested that one uses
>
> > Reduce[13219.56 == 20000/1.95583 * (1 + z)^11, z, Reals]
>
> > But I use Mathematica 4 and it seems that Reduce does not have
> > this option in this Mathematica version.
>
> > Can I anyway constrain the solution space with Mathematica 4?
>
> > Thanks in advance
> > M. Harborth.
>
> The following works
>
> In[1]:=$Version//InputForm
> Out[1]//InputForm="4.2 for Mac OS X (August 22, 2002)"
>
> In[2]:=Select[z/.Solve[13219.56=000/1.95583*(1+z)^11,z],#=E2=88=
=88=
> Reals&]
> Out[2]={0.0236182}
>
> or
>
> In[3]:=Select[Reduce[13219.56=000/1.95583*(1+z)^11,z],Last[#]
> =E2=88=88Reals&]
> Out[3]=z==0.0236182
>
> Sam
Please note that some problems occurred when copying and pasting
#=E2=88=88= Reals&
should be
Element[#, Reals]&
Sam