RE: FindRoot, suppressing complex interval-numbers

*To*: mathgroup at smc.vnet.net*Subject*: [mg70898] RE: [mg70870] FindRoot, suppressing complex interval-numbers*From*: "David Park" <djmp at earthlink.net>*Date*: Wed, 1 Nov 2006 03:55:09 -0500 (EST)

Paul, There are no real roots - not even at such large values of x. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Paul [mailto:pw23 at gmx.net] To: mathgroup at smc.vnet.net Hello, I have the following problem: Take the simple example FindRoot[Sin[x] +2, {x, 1.656 10^8, 1.653 10^8, 1.658 10^8}, EvaluationMonitor :> AppendTo[xs, x]] In the Help we can read: "FindRoot[lhs==rhs, {x, a, a_min, a_max}] searches for a solution, stopping the search if x ever gets outside the range a_min to a_max. " But when I display xs I can see, that there are also two complex numbers used. This is a problem if I use a function (in my case a compiled one) inside FindRoot, which only accepts real numbers. So how can I suppress the using of complex numbers in FindRoot? Best regards, Paul (Mathematica 5.2)