Re: Non linear diff eq
- To: mathgroup at smc.vnet.net
- Subject: [mg15578] Re: [mg15491] Non linear diff eq
- From: jtischer at col2.telecom.com.co (Cl-Jurgen Tischer)
- Date: Tue, 26 Jan 1999 13:44:53 -0500 (EST)
- Organization: Universidad del Valle
- References: <199901180922.EAA20789@smc.vnet.net.>
- Sender: owner-wri-mathgroup at wolfram.com
Francisco, I'm afraid this is not a problem to be solved with Mathematica, but with some easy arguments. Of course Mathematica is of help to find the answer, but only to the extent you don't know elementary functions and elementary DE's. So solve the equation for x positive and for x negative (use Mathematica), both solutions can not oscillate fast at zero, so you have two cases, the function going up or down in zero. If going up, the function is of the form c Sin[t] with positive c, so a has to be positive and equal to c Sin[1], If going down, the function has to be of the type c Sinh[t] with c negative, so a has to be negative and equal to c (E-1/E). Jurgen Fancisco Gutierrez wrote: > > Hi! I have the following nonlinear diff. eq.: x'' + Abs[x]=0, t element > of [0,1], with these boundary conditions: x[0]==0, x[1]==a. > > How can I work it out with Mathematica? > > thanks! > > Francisco Gutierrez >
- References:
- Non linear diff eq
- From: "Fancisco Gutierrez" <rpena@impsat.net.co>
- Non linear diff eq