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Possible Duplicate:
Fourier 1st step?

How to find fourier transform of a series of the such form: $$y_k=\left[f(x) \right]^{2},$$ but I am not sure of the step by step for going about this computation.

how is the first step??

thank you very much!!

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    What is $k$? You don't take Fourier transform of a series.2012-06-18
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    to be specfic, it states $y_{k} = [k-\frac{n-1}{2}]^{2}$ thank you very much!!2012-06-18
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    Wait, where is $x$ in that definition of $y_k$?2012-06-18
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    my error. the true problem is stated with $y_K$ and i wrote question as f(x)...does this answer? i am really lost here!! how do you know when to use integral vs when to use sum to find the transform?2012-06-18

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Integration by parts. You're doing an integral of the form $$ \int (f(x))^2 \exp(i\xi x) dx $$

Let $u = (f(x))^2$ and $dv = \exp(i \xi x)$.

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    Based on nanme's comment and previous question, I find it likely OP means the discrete transform.2012-06-18
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    i think so too!but how to go about this?2012-06-18