What is the graphical representation of a point function?

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Discussion Overview

The discussion revolves around the graphical representation of a point function, particularly focusing on a discontinuous, periodic function with unit values at specific intervals. Participants explore the implications of integrating such functions and the relationship to impulse functions, including the Dirac delta function.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the graphical representation of a function that is nonzero only at a finite or countably infinite number of points, suggesting that its integral would be zero.
  • One participant shares their findings using GeoGebra to simulate an impulse function, indicating that they have derived a graphical representation of the primitive of the function.
  • Another participant questions the clarity of the initial posts and suggests that the discussion may be related to the Dirac delta function, which is characterized as an infinitely high, infinitely thin spike with a total area of one.
  • There is a discussion about the nature of the graph in file 2, with one participant asserting it consists of three points and questioning the integration result.
  • One participant expresses confusion about the Dirac delta function and the concept of controlling the height of a pulse, noting that it seems nonsensical to compare the heights of infinitely high pulses.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the function in question and the implications of integrating it. There is no consensus on the correct interpretation of the graphical representation or the relationship to the Dirac delta function.

Contextual Notes

Participants mention various assumptions and interpretations regarding the graphical representation of point functions and impulse functions, but these remain unresolved. The discussion reflects a lack of clarity on the definitions and properties of the functions being discussed.

Jhenrique
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Hello!

We know how is a primitive of a any function (file 1), but how will be the graphic of a function like the at file 2 (is a descontinued function, periodic with a unit value in a point interval)?
 

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Jhenrique said:
Hello!

We know how is a primitive of a any function (file 1), but how will be the graphic of a function like the at file 2 (is a descontinued function, periodic with a unit value in a point interval)?
Since your function is nonzero only at a finite or possibly countably infinite number of points, its integral will be zero.
 
I found the answer for my question using the geogebra and ploting a simulation of an impulse function and then, integrating and deriving. I found that graphic will be so (file 3).
 

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Jhenrique said:
I found the answer for my question using the geogebra and ploting a simulation of an impulse function and then, integrating and deriving. I found that graphic will be so (file 3).
?
Without some more context here, I have no idea what you're doing.
 
The ideia was that I wanted to know how plote o graphic of a primitive of a function like the file 2. But, how I'm autodidatic and pass the day studing math, I same already found the answer for my doubt (with much sacrifice, as always). The file 3 shows the primitives of a function (blue) with various impulses.
 
Jhenrique said:
The ideia was that I wanted to know how plote o graphic of a primitive of a function like the file 2. But, how I'm autodidatic and pass the day studing math, I same already found the answer for my doubt (with much sacrifice, as always). The file 3 shows the primitives of a function (blue) with various impulses.
I don't think so, at least not on the basis of what you posted in file2. I think what you're talking about is the Dirac delta function (http://en.wikipedia.org/wiki/Dirac_delta_function).
Emphasis added by me.
The delta function is sometimes thought of as an infinitely high, infinitely thin spike at the origin, with total area one under the spike, and physically represents an idealized point mass or point charge.

Your file2 graph seems to me to be three points. If you integrate that, you get zero. If you're talking about unit impulses, which are related to the Dirac delta function, you need to tell us that.
 
Mark44 said:
Your file2 graph seems to me to be three points. If you integrate that, you get zero. If you're talking about unit impulses, which are related to the Dirac delta function, you need to tell us that.
When I opened this topic, I don't was thinking in delta function, because I didn't understood how it works, so, I was trying to develop other way to arrive at same answer. Now I understood how the delta and heaviside functions works, but not perfectly, because I hoped to able to control the height of a pulse... How I can say if a pulse is bigger than other if all pulses are equal to ∞ ?? It's no make sense to me.
 

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