Solving Three-term Integral with Constants

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Discussion Overview

The discussion revolves around solving a complex three-term integral involving constants and specific forms of functions. Participants explore methods for integrating the expression analytically, considering the challenges posed by the constants and the nature of the exponents involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant presents a specific integral form and expresses difficulty in solving it analytically, particularly due to the complexity of the constants and the requirement for a non-numerical solution.
  • Another participant questions the validity of the constants and exponents in the integral, suggesting that the expression may be overly complicated and proposing a simplified form for consideration.
  • There is a suggestion to use the binomial formula for expansion and integrate term by term, although concerns are raised about the accuracy of such an approach requiring a high order of expansion.
  • A later reply clarifies that the exponent \(\frac{\eta}{3-\kappa}\) is a negative, non-integer value, which may influence the integration process and the feasibility of finding an analytical solution.
  • Participants express uncertainty about the existence of an analytical solution and mention the possibility of consulting integral tables, though skepticism about their usefulness is noted.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best approach to solve the integral, and multiple competing views on the validity of the constants and the potential for analytical solutions remain unresolved.

Contextual Notes

Limitations include the dependence on the specific values of the constants and exponents, as well as the unresolved nature of the mathematical steps required for integration.

Proteoglycan
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Hello

I've been having some difficulty solving a three-term integral of the form:


[tex]\int^{\beta_{r}}_{\beta_{0}}\frac{y^{\tau-3+\frac{\eta}{3-\kappa}}}{\left(1-y^{2}\right)^{3-\frac{\tau}{2}}}\left(1+\left(\frac{1}{(3-\kappa)N}-\frac{1}{\beta_{0}}\right)y\right)^{-\frac{\eta}{3-\kappa}}dy[/tex]

Where [tex]y < 1[/tex] and [tex]\beta_{0}, \tau, \eta, \kappa, N[/tex] are constants.

I've tried expanding the term:
[tex]\left(1-y^{2}\right)^{3-\frac{\tau}{2}}}[/tex]
As a taylor series and then integrating term by term, although for this to be accurate this tends to require an expansion up to an order of 40 which cannot be done using Mathematica. It is also required that this integral be done non-numerically and expressed in terms of the limits of the integral.

It is also quite difficult expressing the solution using hypergeometric functions (eg 2F1) using these limits.

Any help would be greatly appreciated!
 
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dude you have way to many different constants in there

is this correct:

[tex]\int^{\beta_{r}}_{\beta_{0}}\frac{y^k}{\left(1-y^{2}\right)^n}\left(1+ly\right)^{m}dy[/tex]

is [itex]\frac{\eta}{3-\kappa}[/itex] and integer? a positive integer? what about all the screwy looking exponents you have? can you expand using the binomial formula and then integrate those term by term?
 
ice109 said:
dude you have way to many different constants in there

is this correct:

[tex]\int^{\beta_{r}}_{\beta_{0}}\frac{y^k}{\left(1-y^{2}\right)^n}\left(1+ly\right)^{m}dy[/tex]

is [itex]\frac{\eta}{3-\kappa}[/itex] and integer? a positive integer? what about all the screwy looking exponents you have? can you expand using the binomial formula and then integrate those term by term?

I would take this form to an integral table. It's most likely too complex to find there though.
 
like i said - it depends on the exponents
 
Thanks for the replies,

The integral could be expressed in that simplified form and [tex]\frac{\eta}{3-\kappa}[/tex] would be be a negative, non-integer value. I could expand either the term [tex]\left(1-y^{2}\right)^{n}[/tex] or [tex]\left(1+ly\right)^{m}[/tex] and integrate term by term, although for this to be accurate it tends to require an expansion up to an order of 40. I was hoping there might be an analytical solution to this or a better approximation, although I can see this might be unlikely in this case.
I've tried looking through an integral table although I've not had much luck so far.
 

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