Integrating odd functions with infinite discontinuity:

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Discussion Overview

The discussion centers around the integration of odd functions that exhibit infinite discontinuities within their domains. Participants explore whether such integrals can yield convergent finite results, particularly in the context of improper integrals and the Cauchy Principal Value.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions if an odd function with an infinite discontinuity can be integrated over its domain to yield a convergent finite result, using specific examples.
  • Another participant suggests looking into improper integrals as a potential framework for understanding the issue.
  • A participant acknowledges that the integrals discussed are indeed improper but expresses uncertainty about their convergence or divergence, noting a geometric intuition that suggests convergence.
  • Another participant introduces the concept of the Cauchy Principal Value, indicating that while the integrals over discontinuities are divergent, they can be assigned a value that aligns with geometric intuition.
  • A later reply expresses gratitude for the clarification provided regarding the Cauchy Principal Value.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the integrals converge or diverge, with multiple competing views and interpretations of the concepts involved.

Contextual Notes

The discussion involves assumptions about the behavior of integrals at points of discontinuity and the implications of using the Cauchy Principal Value, which may not be universally accepted or applicable in all contexts.

atqamar
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If an odd function has an infinite discontinuity in its domain, can it be integrated (such that a convergent finite emerges) with that domain included?

For example: [tex]\int_{-1}^2 \frac{1}{x^{-3}} dx[/tex]. Intuitively, it can be simplified to [tex]\int_1^2 \frac{1}{x^{-3}} dx[/tex] and thus the infinite discontinuity at 0 is removed.

If that is not doable, can an integral converge if the end points of the domain are infinite discontinuities?

For example: Does [tex]\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}} tan(x) dx = 0[/tex]?

If these kinds of functions are split in two, and limits to [tex]\infty[/tex] are taken, then algebraic manipulation of infinities are required.

Any insight would be appreciated.
 
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You should look into improper integrals?
 
Certainly, these are all improper integrals. But my question is whether the above integrals would converge or diverge. Intuitively/Geometrically, they should converge; but like I said, once the improper integral is carried out, one has to deal with infinities.
 
Look up "Cauchy Principal Value". Strictly, the integrations over the discontinuities are divergent, but they can be assigned a Cauchy Principal Value that appeals to your geometric intuition.
 
Thanks a lot Gib Z! That helped immensely.
 

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