Re: odd mathematica blindspot
- To: mathgroup at smc.vnet.net
- Subject: [mg56484] Re: [mg56468] odd mathematica blindspot
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Tue, 26 Apr 2005 21:52:39 -0400 (EDT)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
$Version
5.1 for Mac OS X (January 27, 2005)
Off[Solve::ifun];
x/.(Solve[(999999999999/10000000000000)^x\[Equal].5,x]//Flatten)
0.30103
x /. (Solve[(999999999999/10000000000000)^x\[Equal]1/2,x]//Flatten)
Log[2]/Log[10000000000000/999999999999]
%//N
0.30103
Bob Hanlon
>
> From: Edward Peschko <esp5 at pge.com>
To: mathgroup at smc.vnet.net
> Date: 2005/04/26 Tue AM 01:33:53 EDT
> Subject: [mg56484] [mg56468] odd mathematica blindspot
>
> hey all,
>
> I was wondering why the following didn't output any solutions. I'd think
> it would be easy:
>
> Solve[(999999999999/10000000000000)^x == .5, x]
>
> It gives no solutions. What's really odd is when you say:
>
> Solve[(999/1000)^x==.5, x]
>
> which *does* give solutions, in the form:
>
> {{x -> 692.801... }}
>
> Also, just curious, but how do you extract 'x' from the above?
> Say I wanted to plug the above solution into another equation..
> In perl I'd say something like:
>
> y = Solve[(999/1000)^x == .5, x];
>
> 3 * y->{x} # replaces with 692.81
>
> etc. etc.
>
> but this doesn't seem to work. How do you access parts of a mathematica
> datastructure/hash?
>
> And finally, how do you set values with the tty? ie: suppose my backspace
and
> delete key aren't working with math.exe (they aren't) and I want them to
> delete typos. In unix this would be stty erase ^H. In mathematica...?
>
> Thanks much for any help,
>
> Ed
>
>