Thanks for your reply, Ilya!
I kind of know, that I am writing my request in a wrong form. I just want to know how to write it right.
First of all, unfortunately, I don't have Mathematica, my question is about Wolfram Alpha only.
Second, I already tried what you suggested - please see my attached screenshot for details. Downloaded file is called "c.txt".
Third, I failed to watch your file "FourierDCT.nb" in my CDF player (version 188.8.131.52).
Error message is,
FourierDCT::fftl: "Argument \!(\"-1.000000000000000000e+00 0.000000000000000000e+00\\n-9.949874686716791983e-01 0.000000000000000000e+00\\n-9.899749373433583965e-01 0.000000000\" [Ellipsis] \"3433581745e-01 2.958823122697410227e-02\\n9.949874686716790873e-01 2.215147684345047940e-02\\n1.000000000000000000e+00 1.559357775423273439e-02\") is not a non-empty list or rectangular array of numeric quantities."
Could you please save it in some sort of compatibility mode?