Re: solution of equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg116390] Re: solution of equation*From*: Peter Breitfeld <phbrf at t-online.de>*Date*: Sun, 13 Feb 2011 03:05:40 -0500 (EST)*References*: <ij5mvj$jo5$1@smc.vnet.net>

Piotr Munik wrote: > Dear Math Group, > > > > I want to solve equation like this: > > L := 100; h := 1; > > n Tan[n L] == h > > > > I need roots of this equation in a list form > > > > but I have a problem. > > > > I try findfoot > > FindRoot[n Tan[n L] == h, {n, 0.01}] > > but it's not good > > > > I need your help... > > > Piotr > > Try Reduce: sols={ToRules@Reduce[{n Tan[n L] == h, 0. <= n <= 1}, n]} Out={{n -> 0.0155525}, {n -> 0.0466577}, {n -> 0.0777637}, {n -> 0.108871}, {n -> 0.139981}, {n -> 0.171093}, {n -> 0.202208}, {n -> 0.233327}, {n -> 0.26445}, {n -> 0.295577}, {n -> 0.326709}, {n -> 0.357847}, {n -> 0.388989}, {n -> 0.420138}, {n -> 0.451292}, {n -> 0.482452}, {n -> 0.513618}, {n -> 0.54479}, {n -> 0.575969}, {n -> 0.607154}, {n -> 0.638345}, {n -> 0.669543}, {n -> 0.700746}, {n -> 0.731956}, {n -> 0.763171}, {n -> 0.794393}, {n -> 0.82562}, {n -> 0.856853}, {n -> 0.888092}, {n -> 0.919336}, {n -> 0.950585}, {n -> 0.981839}} I wrote "0." instead of "0" in the inequality to get Reals in the results instead of Root-objects. -- _________________________________________________________________ Peter Breitfeld, Bad Saulgau, Germany -- http://www.pBreitfeld.de