Re: Solve transcendental functions
- To: mathgroup at smc.vnet.net
- Subject: [mg21190] Re: Solve transcendental functions
- From: Niels Sandmann Pedersen <sandmann at imada.sdu.dk>
- Date: Fri, 17 Dec 1999 01:23:57 -0500 (EST)
- Organization: UNI-C
- References: <831v41$g3d@smc.vnet.net> <385558EC.CD39697C@wolfram.com>
- Sender: owner-wri-mathgroup at wolfram.com
> You can find solutions for particular values of a, provided you supply a
> starting point for a Newton-type iteration.
>
> f[x_,a_] := x^2-2Cos[a*x]/a
> parametrizedSolve[f_, a_?NumberQ, init_] :=
> FindRoot[Evaluate[f[x,a]==D[f[x,a],x]], {x,init},
> AccuracyGoal->15, WorkingPrecision->20]
>
> For example, if I want to handle the case where a is 1, starting near
> x=2, I can do as below.
>
> In[110]:= parametrizedSolve[f, 1, 2]
> Out[110]= {x -> 2.1999981850434100730}
>
thanks, it works very well. But what if I need all the solutions in an
interval, or maybe all solutions (if not infinite) ?
--
Mvh, Niels Sandmann