# Help required to find roots of a complex function in Mathematica 6

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• May 20th 2009, 09:59 AM
kumar.kannan
Help required to find roots of a complex function in Mathematica 6
I am a new user of Mathematica, I am trying to solve a dispersion relation in Mathematica which is a function of omega and wave number, my omega is a complex frequency. I am trying to solve it in the way as shown below

r=0.01;
we=1000;
oh=0.1;
k=.;
n=.;
m=sqrt(k^2+n^2);

F[ome_]=(ome+I (we)0.5 k+4 m2 oh)*(ome+I (we)0.5 k) Tanh[m]+4 m3 oh2 *(m Tanh[m]-(m^2+(ome+I (we)^0.5 k)/oh)0.5 *Tanh[(m^2+(ome+I (we)^0.5 k)/oh)0.5])+r ome2+m3;
t=Table[{k,Re[ome/.FindRoot[F[ome]Š0,{ome,{(1.5+50 I),(3+100 I)}},MaxIterations®500]]},{k,1,100,1}]

ListPlot[t,PlotJoined®True]

I want to make a plot with the real part of the ome on the y axis and k on the x axis.

It is very important for me to solve this function, so any help is appreciated.My email i.d is kumar.kannan@uni.lu. Any help or persons willing to help may also contact me on my email i.d for further discussions. I am having problem in selecting the intial guess root. i am attaching a graph for reference.
Any suggestions will be helpfult to me as I have been trying to solve this equation since a week. I will also provide the equation, if required.Please help is needed.
bye
with regards
K.Suresh kumar
• May 20th 2009, 10:08 AM
kumar.kannan
Help required to find the roots of this equation in Mathematica 6
Hello everybody,
I am attaching the original equation with this mail,please any suggestions on how to solve this equation will be very helpful to me in mathematica. The equations in the figure have an explanationin the bottom. I would like to have further discussions on solving this equation in Mathematica
bye
with regards
K.Suresh kumar