Re: 2nd order differential equation help
- To: mathgroup at smc.vnet.net
- Subject: [mg31481] Re: 2nd order differential equation help
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 8 Nov 2001 04:54:15 -0500 (EST)
- Organization: Universitaet Leipzig
- References: <9sb4rb$h1n$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hmm,
a second order equation needs two initial conditions ?
What is your eqn1[t_] doing ?
DSolve[{g''[t] + 0.1g'[t] + g[t] == 0,
g'[0]==1,
g[0]==0},
g[t]
]
Regards
Jens
Peter Dimitriou wrote:
>
> Exactly how do I get this into a form Mathamatica will accept? It has
> been a number of years since enrolling in diffeq, however I think I am
> close to correct but would appreciate help.
>
> the problem;
>
> Solve the differential equation:
>
> g''(t) + 0.1 g'(t) + g(t) = 0
>
> where the previous equation uses conventional mathematical notation.
> You must transfrom the equation and initial conditions into
> Mathematica syntax.
>
> for t between 0 and 10 Pi
>
> subject to the initial conditions
> g(0) = 0,
> g'(0) = 1
>
> Plot your results.
>
> My attempt is as follows:
>
> Clear[g]
>
> Clear[eqn]
>
> eqn[t_] = g''[t] + 0.1g'[t] + g[t] == 0
>
> Clear[eqn1]
>
> eqn1[t_] = g'[t] + 0.1g[t] + ?g[t] == 0
>
> solution = DSolve[{eqn[t], eqn1[t]}, g'[0] == 1,
> g[0] == 0, g[t], {t, 0, 10\[Pi]}]
>
> DSolve::dsvar: g[0]==0 cannot be used as a variable.
>
> what am I dont doing right? any suggestions helpful