Let's say, there is a sum $\Sigma^{\infty}_{k=1} \frac{\cos 2k x}{\sqrt{2k \ln 2k}}$, how do I prove or disprove that it is a Fourier transformation for some function? Any ideas or online sources are welcome.
2026-04-02 01:01:56.1775091716
How do I prove or disprove that the series are Fourier transformation for some function: $\sum^{\infty}_{k=1} \frac{\cos 2k x}{\sqrt{2k \ln 2k}}$
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