FindRoot with algebraic expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg122808] FindRoot with algebraic expressions
- From: Mirko <dashiell at web.de>
- Date: Fri, 11 Nov 2011 04:54:10 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Hi,
I was wondering how FindRoot works when trying to use a algebraic initial point.
I.e.:
FindRoot[h[theta]==0,{theta[m], ???}]
where h is function of theta, for example:
h[theta_]=1/(1-m)*theta[m]
(notice that this is for a given m).
What should I use as a starting point?
If I just use 1 as a starting point, it returns a mistake. However, I could use the solution of a first step approximation, but it doesn't work as well. Here is what I mean:
t0=Solve[h1[theta]==0,theta[m]]
(where h1 is a different function, similar to h).
Plugging t0 into ??? returns a mistake as well. This is probably due to the format?
Although, even if I use
theta[m]/.Solve[h1[theta]==0,theta[m]]
and plugging theta[m] into ??? gives me a mistake.