What is the value of the impulse function?

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The discussion centers on the confusion surrounding the delta function's value being infinite while having a finite amplitude in graphs. Participants clarify that the delta function has an infinitely high amplitude but an infinitesimal width, meaning its area is finite and equal to the amplitude. The correct expression for the Fourier transform of a shifted impulse function is confirmed as 3δ(f-5) + 3δ(f+5). The inverse Fourier transform of this expression results in a cosine wave with a frequency of 5 Hz and an amplitude of 6. Understanding the area under the delta function is crucial to grasping its properties.
clw
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Homework Statement


I am confused with the idea that the value of a delta function is infinity but when given a graph why is there an amplitude/magnitude value for the delta function. I have attached a graph. Assuming the phase is zero I'm trying to write a Fourier transform for it.

Homework Equations



G(f) = |G(f)| e^{j\vartheta}

The Attempt at a Solution


I know that it is a shifted impulse function so would it just be 3δ(f-5)+3δ(f+5)? Any help would be very much appreciated I'm just having a hard time grasping the idea of impulse function having an infinite value but there's an amplitude of 3?
 

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clw said:

Homework Statement


I am confused with the idea that the value of a delta function is infinity but when given a graph why is there an amplitude/magnitude value for the delta function. I have attached a graph. Assuming the phase is zero I'm trying to write a Fourier transform for it.

Homework Equations



G(f) = |G(f)| e^{j\vartheta}

The Attempt at a Solution


I know that it is a shifted impulse function so would it just be 3δ(f-5)+3δ(f+5)? 3?

Your expression is correct.

The delta function has arbitrarily high amplitude but also arbitrarily small spread. The area is what matters.

If you take the inverse Fourier transform of your expression you would get 6cos[2π(5)t]. So what you are displaying is the Fourier transform of a cosine wave with frequency = 5 Hz and amplitute = 6.
 

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