Why is the Fourier transform of 1 the 2pi*dirac(w) function

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The Fourier transform of the constant function 1 is 2πδ(w) because it represents a signal with no oscillation, corresponding to zero frequency. The Dirac delta function δ(w) indicates that all the signal's energy is concentrated at zero frequency. The factor of 2π arises from normalization conventions in Fourier transform definitions. Different conventions exist, but the key point is that the transform reflects the nature of the original function. Understanding these concepts clarifies why a constant function translates to a delta function in the frequency domain.
thomas49th
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Homework Statement


Hi, I was wondering why the Fourier transform of 1 is

2\pi\delta(w)

I would of though that one would be of infinite frequencies (like a square wave).

Further more if g(t) = 1, for all t, g(t) = 1. Why does the Fourier transform have the argument of g(t) = 1 have an argument (w). g(t) has no frequency!

Thanks
Thomas
 
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Wouldn't g(t)=1 have only zero frequency? It never oscillates at all. And isn't delta(w) the function in the frequency domain that only has zero frequency? It's only 'nonzero' at w=0. Make perfect sense to me.
 
Last edited:
good intuition. May I ask where the 2pi comes from again :)
 
thomas49th said:
good intuition. May I ask where the 2pi comes from again :)

It's a normalization of the Fourier transform. There's more than one convention for doing that. What's yours? I thought this question was more about intuition. The 2*pi has nothing to do with that. Take the inverse Fourier transform of 2*pi*delta(w). Do you get 1?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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