Re: What am I doing wrong with this code?
- To: mathgroup at smc.vnet.net
- Subject: [mg82535] Re: What am I doing wrong with this code?
- From: Peter Pein <petsie at dordos.net>
- Date: Wed, 24 Oct 2007 04:23:11 -0400 (EDT)
- References: <ffkffr$spa$1@smc.vnet.net>
sean_incali schrieb:
> I think I'm having a brain fart. Seriously...
>
> Plot[{1/(1 + y^2), (1/y - 1)^(1/2)}, {y, 0, 5}]
>
> What is wrong with that code? Maybe it's not solvable in mathematica?
>
> I'm trying to plot nullclines of a system of ODEs. and those function
> up there are them. I just can't get mathematica to plot them in the
> same graph.
>
> I get an error message saying...
>
>>From In[22]:=
> (1/y - 1)^(1/2) is not a machine-size real number at y =
> 1.0000001666666667`.
>
> Any help is appreciated.
>
> sean
>
>
The complex numbers are _not_ a subset of the real numbers:
In[1]:=
(1/y - 1)^(1/2) /.
y -> 1.0000001666666667
Out[1]=
0. + 0.00040824825649889477*I
... and air your room ;-)
Peter