A basic question about RecurrenceTable - warning messages

*To*: mathgroup at smc.vnet.net*Subject*: [mg122235] A basic question about RecurrenceTable - warning messages*From*: victorphy <vbapst at gmail.com>*Date*: Fri, 21 Oct 2011 07:28:36 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hello, I have a small and basic question about RecurrenceTable. I would like to solve f(x,a)==0 where x is the unknown and a is a parameter. As f has several zeros I want to follow one zero when varying a. Thus I write something like that : f[x_,a_] := -(x - a)^3 + (x - a) soltest[a_, b_] := x /. FindRoot[f[x, a], {x, b}] RecurrenceTable[{a[n + 1] == soltest[n/10, a[n]], a[0] == -1}, a, {n, 10}] I get the correct output but a lot of warning messages : FindRoot::srect: "Value a[n] in search specification {x,a[n]} is not a number or array of numbers ReplaceAll::reps: "{FindRoot[f[x,n/10],{x,a[n]}]} is neither a list of replacement rules nor a valid dispatch table, and so cannot be used for replacing Is there something that I am doing wrong ? Or is it just normal ? Thank you very much for your answers. Victor