Re: DSolve difficulties ...
- To: mathgroup at smc.vnet.net
- Subject: [mg111860] Re: DSolve difficulties ...
- From: Helen Read <hpr at together.net>
- Date: Sun, 15 Aug 2010 07:40:07 -0400 (EDT)
- References: <email@example.com>
- Reply-to: HPR <read at math.uvm.edu>
On 8/14/2010 6:33 AM, Slide wrote: > Yesterday I typed in the following command line, into the student > version of Mathmatica . > > DSolve[y''[x] == 1/(y[x]*y[x]), y[x], x] > > and got a complicated Solve command and expression back with the > comment 'The equations appear to involve the variables to be solved > for in an essentially non-algebraic way.' I get a perfectly good solution. > OK, that was yesterday, fortunately I didn't close the session. > > However, now when I try the same command, I get a null response. Try it in a fresh session. Remember that Mathematica remembers everything you do in a session, and you might have done something that defined x or y or y[x] in some way. -- Helen Read University of Vermont