Re: Q
- To: mathgroup at smc.vnet.net
- Subject: [mg41478] Re: Q
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Wed, 21 May 2003 08:04:25 -0400 (EDT)
- Organization: The University of Western Australia
- References: <ba5176$sfi$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <ba5176$sfi$1 at smc.vnet.net>,
Stepan Yakovenko <yakovenko at ngs.ru> wrote:
> I've got an equation f'[t]=F[f[t]].
> F[] is known and analytic, (say
> F[x]=x*x). I know f[0]=f0. f0 is
> a number. I want to get all f'[0],
> f''[0], f'''[0], ... assigned
> to their numberical values that can be
> unambiguously found after differentiating
> the source equation as many times as
> needed.
Instead of using F (which will cause problems in TraditionalForm), I've
used g.
The following code determines the f'[0],..., Derivative[m][f][0] in
terms of f[0] as replacement rules (which is usually better than
assigning them as numerical values):
m=4;
Solve[f'[t] - g[f[t]] + O[t]^m == 0,
Table[Derivative[n][f][0], {n, m}]]
Cheers,
Paul
--
Paul Abbott Phone: +61 8 9380 2734
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