RE: FindRoot s all

*To*: mathgroup at smc.vnet.net*Subject*: [mg49418] RE: [mg49415] FindRoot s all*From*: "David Park" <djmp at earthlink.net>*Date*: Mon, 19 Jul 2004 07:46:08 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

This is another case where I find Ted Ersek's RootSearch package more convenient. y[u_, c_] = c^u - u^c - 1 ; Plot[y[x, 2], {x, -5, 5}]; Needs["Enhancements`RootSearch`"] RootSearch[y[x, 2] == 0, {x, -5, 5}] {{x -> 0.}, {x -> 1.}, {x -> 4.25746}} The package may be obtained at http://library.wolfram.com/infocenter/MathSource/4482/. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Narasimham G.L. [mailto:mathma18 at hotmail.com] To: mathgroup at smc.vnet.net y[u_,c_]=c^u-u^c-1 ; Plot[y[x,2],{x,-5,5}]; FindRoot[y[x,2]==0,{x,-5,5}]; " Solution settles to a value outside the interval of roots of its derivative (humps and valleys),it may be the problem of Newton-Raphson diverging tangets.How to capture all roots [in this case {x -> 0, 1}] ? It should be valid for all c." TIA