Re: Solving the system with inexact coefficients

*To*: mathgroup at smc.vnet.net*Subject*: [mg99383] Re: [mg99335] Solving the system with inexact coefficients*From*: "David Park" <djmpark at comcast.net>*Date*: Mon, 4 May 2009 06:02:07 -0400 (EDT)*References*: <30708295.1241344271268.JavaMail.root@n11>

It looks like something you have to use FindRoot on. Or better yet Ted Ersek's RootSearch package from MathSource at the WRI site. (With changes in 7.0.1 RootSearch now gives a warning message that can usually be ignored. It is too bad because RootSearch is much better than FindRoot for root searching in 1-dimension.) David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Desana [mailto:incolaster at gmail.com] Hello, this is my problem : I've got cca 40 sinusoidal waves ( e.g. 0.118149 Cos[25.1013 t]) and after superposition I get irregurar wave record. I'm trying to see how many waves I have in certain interval by finding how many zero crossings there are: Reduce[Total[Subscript[\[Eta], i]] == 0 && 0 < t < 60, t] but I couldn't because "Reduce was unable to solve the system with inexact coefficients" What's the problem? What does it mean? Can I find intersection between my wave and x-axis in any other wave? Perhaps graphically ? Thank you, student Desana