Re: Multiple FindRoot

*To*: mathgroup at smc.vnet.net*Subject*: [mg109828] Re: Multiple FindRoot*From*: "David Park" <djmpark at comcast.net>*Date*: Wed, 19 May 2010 07:03:58 -0400 (EDT)

You might try Ted Ersek's RootSearch package from WRI MathSource. It is much more convenient than FindRoot for such cases. David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: EF [mailto:he.frauendorfer at t-online.de] Find Lambda Values for Tan[Lambda] == -([Lambda]/h) and e.g. h = 0.5 the first 10 Lambda Values for h = 0.5 are In[27]:=Lambda = Out[27]= {1.837, 4.816, 7.917, 11.04, 14.17, 17.31, 20.44, 23.58, 26.72, 29.86} My solution requires 1) FindRoot for a wide range of starting (ending) values 2) Eliminate the great number of double real solutions 3) Verify solutions, there are "some" wrong values Is there a more direct way to the correct lambda values? E.F.