Hey Sreeraj, which version of Mathematica are you using? `ReIm` is a function the was introduced in 10.1 and I always forget to mention that my code runs on the latest version 11.1. In this case, the fix is easy, define the `ReIm` function yourself ReIm[x_?NumericQ] := {Re[x], Im[x]}; ReIm[x_] := x; As for your other question, this can easily be done, but you have to remember, that your root might be a complex number. Let's say you want to plot your `k` against the real part of the first root, you can use: data = Table[Flatten@{k, roots}, {k, 0.01, 1, .01}]; ListPlot[Re@data[[All, {1, 2}]]]

It means: take `All` values from the 1st and 2nd column of data and calculate their `Re`al part. Since your `k` are real anyway it doesn't matter and from the first roots (in the 2nd column) all real parts are taken. This is then plotted, which gives you a graph of `k` against the real-part of the first root.

Thanks a lot Patrick Scheibe. And sorry for delay in replying...

Thanks for putting efforts to solve my problem. I would like to point out that in the exported file there are terms like "ReIm[-1.1653855769993797]". How to get rid of "ReIm[]" and print only "-1.1653855769993797". On a different topic, I would like to ask one more question . If you replace the code "data = Table[Flatten@{k, ReIm /@ roots}, {k, 0.01, 1, .01}];" with "data = Table[Flatten@{k, roots}, {k, 0.01, 1, .01}]" you can see the whole data listed out. How can i plot a graph with k along x axis and only one root, say first one, in y axis? Thanks in advance...

[?] Separate out the real and imaginary part and export data?