Master's Thesis

What I hate is when books say that something is clear, what definitely is not clear! So, why is it clear that for and ? It seems to have something to do with the differentiation rules of the Fourier transform, and I couldn’t verify the mentioned equation yet. As far as I can see, it really is not that trivial that a simple clear-ness is justified.

This claim came together with , the proof of which also doesn’t seem to be too trivial. What still confuses me is the symbolism .