Re: O.D.E in Power Series
- To: mathgroup at smc.vnet.net
- Subject: [mg18276] Re: O.D.E in Power Series
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 25 Jun 1999 15:05:22 -0400
- Organization: Universitaet Leipzig
- References: <7ku0dk$9a1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Alan,
if you want a general infinite power series you should try
the SpecialFunction.m package from MathSource.
If a solution to the first order terms is sufficient
for you than
deqn=y''[x]-2(x+3)y'[x]-3y[x]==0;
order=10;
Solve[LogicalExpand[
deqn /.Thread[ {#,D[#,x],D[#,{x,2}]} & /@ (
y[x]->Sum[a[i]*x^i,{i,0,order}]+O[x]^(order+1))]],
Table[a[i],{i,2,order}]]
will do it.
Regards
Jens
ALAN S BLOOM wrote:
>
> I am trying to solve this equation below:
> y''-2(x+3)y'-3y=0 with the DSolve command.
>
> DSolve [y''[x]-2(x+3)y'[x]-3y[x]==0,y[x],x]
>
> How can I make it work?
>
> Alan