Re: odd mathematica blindspot
- To: mathgroup at smc.vnet.net
- Subject: [mg56491] Re: odd mathematica blindspot
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Tue, 26 Apr 2005 21:52:53 -0400 (EDT)
- Organization: Uni Leipzig
- References: <d4klbs$eg7$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, try Solve[(999999999999/10000000000000)^x == 1/2, x] and don't mix floating point numbers with symbolic calculations. Regards Jens "Edward Peschko" <esp5 at pge.com> schrieb im Newsbeitrag news:d4klbs$eg7$1 at smc.vnet.net... > 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 >