Fourier transform limit of finite signal

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SUMMARY

The discussion centers on proving that the limit of the Fourier Transform S(w) of a finite energy signal s(t) approaches zero as w approaches infinity, expressed mathematically as \lim_{w \to \infty } S(w) = 0. The participants reference the definition of the Fourier Transform, which is given by the integral \ints(t)e^{-jwt}dt, and the condition that the energy of the signal, represented by ∫|s(t)|²dt, is finite. The mention of Parseval's theorem indicates a potential method for the proof, although the original poster expresses uncertainty about the approach.

PREREQUISITES
  • Understanding of Fourier Transform and its mathematical definition
  • Knowledge of finite energy signals and their properties
  • Familiarity with Parseval's theorem and its implications
  • Basic calculus skills for evaluating integrals
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  • Study the properties of Fourier Transforms for finite energy signals
  • Review Parseval's theorem and its application in signal processing
  • Learn about the implications of the Riemann-Lebesgue lemma in Fourier analysis
  • Practice solving problems involving limits of Fourier Transforms
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Students studying signal processing, electronics engineers preparing for exams, and anyone interested in the mathematical foundations of Fourier analysis.

omaciu
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So this is a very simple question that I am having some trouble figuring out:

Let s(t) be a finite energy signal with Fourier Transform S(w).
Show that \lim_{w \to \infty } S(w) = 0

We know by definition that the FT of this signal is \ints(t)e^{-jwt}dt and also that ∫|s(t)|2dt < ∞.

I'm a little lost on how I can start proving this. I thought about something using Parseval's theorem but I have no idea. Or maybe I can use the FT in it's ∫s(t)cos(wt)dt - j∫s(t)sin(wt)dt form? I have no idea. I'm sure the solution is much simpler than I think it is.
 
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Nobody has any clue? I'm still stuck. I'm studying for an Electronics Math exam and this question (from a past exam) is really stumbling me.
 

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