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Re: Solving the system with inexact coefficients


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




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