Integral Approximation: Tau <<T

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    Approximation Integral
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Discussion Overview

The discussion revolves around the conditions under which certain integral relations hold true when tau is much smaller than T. Participants explore the implications of this condition on the integrals involving a function v(t) and exponential terms, focusing on whether specific equalities or approximations can be established.

Discussion Character

  • Technical explanation, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant questions whether the assumption that tau is much smaller than T is sufficient to establish the truth of the proposed integral relations.
  • Another participant suggests that demonstrating the periodicity of the integrand with respect to T/(1+a) is necessary to validate the relations.
  • A later reply presents a modified version of the integral after substituting for v(t) and asks if this is sufficient to determine the validity of the equality.
  • One participant asserts that if the integral is in its final form, it is adequate to conclude that the equality holds.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the initial assumptions are sufficient to establish the integral relations. Multiple viewpoints are presented regarding the necessity of periodicity and the form of the integral.

Contextual Notes

The discussion highlights potential limitations in the assumptions made about the integrand and its periodicity, as well as the dependence on the specific form of v(t). Unresolved mathematical steps remain regarding the implications of these assumptions.

EngWiPy
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Hello,

If tau<<T which of the following relations are true:

\int_{\tau/(1+a)}^{(T+\tau)/(1+a)}v(t)e^{-j2\pi f_0 at}e^{-j2\pi\frac{k}{T}t[1+a]}\,dt=\int_{0}^{T/(1+a)}v(t)e^{-j2\pi f_0 at}e^{-j2\pi\frac{k}{T}t[1+a]}\,dt

or

\int_{\tau/(1+a)}^{(T+\tau)/(1+a)}v(t)e^{-j2\pi f_0 at}e^{-j2\pi\frac{k}{T}t[1+a]}\,dt\simeq\int_{0}^{T/(1+a)}v(t)e^{-j2\pi f_0 at}e^{-j2\pi\frac{k}{T}t[1+a]}\,dt

Thanks
 
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Your assumtion is not enough to show one of the relations is true. It seems you need to show that the integrand is periodic with T/(1+\alpha).
 
jashua said:
Your assumtion is not enough to show one of the relations is true. It seems you need to show that the integrand is periodic with T/(1+\alpha).

OK, the integral after substituting for v(t) will look like:

\int_{\tau/(1+a)}^{(T+\tau)/(1+a)}e^{j2\pi\frac{m-k}{T}t[1+a]}\,dt

Is that enough to tell now?

Thanks
 
If that is the final version of the integral then it is enough to say that the equality holds.
 

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