How can I easily compute the integral of a hypergeometric function?

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Discussion Overview

The discussion revolves around the computation of the integral of a hypergeometric function, specifically in the context of a given equation involving constants. Participants explore methods for evaluating this integral, including the use of special functions and numerical integration techniques.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant presents an integral equation involving constants and seeks assistance in solving it.
  • Another participant states that the integral cannot be expressed with elementary functions and requires special functions, specifically mentioning the Gaussian Hypergeometric function (2F1) and the incomplete Beta function.
  • A later reply reiterates the need for special functions and requests clarification on how to arrange these functions for calculation, providing specific parameter values and an interval for integration.
  • Some participants suggest that numerical values of hypergeometric functions can be computed using series expansion, although they note this method is tedious.
  • It is proposed that using mathematical software like Mathematica or numerical integrators is a more efficient approach for calculating the integral.
  • One participant expresses gratitude for the advice and indicates they will use WolframAlpha for their calculations.

Areas of Agreement / Disagreement

Participants generally agree that the integral requires special functions and that numerical integration is a viable approach, but there is no consensus on the specific methods or procedures to be used.

Contextual Notes

Participants mention the complexity of the integral and the limitations of expressing it in terms of elementary functions, indicating a reliance on special functions and numerical methods.

Who May Find This Useful

Individuals interested in advanced calculus, numerical methods, or those working with hypergeometric functions may find this discussion relevant.

giuseppesk82
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I am trying to solve the integral of the following equation:

y= a + (b/(1+(x/c)^d)

with a,b,c,d as constant

I will apprecciate your help

Thanks
 
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This indefinite integral cannot be expressed with a combination of a finite number of elementary functions. It requires special functions, namely the Gaussian Hypergeometric function (2F1), or another special function of lower level namely the incomplete Beta function (but in complex domain).
 

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JJacquelin said:
This indefinite integral cannot be expressed with a combination of a finite number of elementary functions. It requires special functions, namely the Gaussian Hypergeometric function (2F1), or another special function of lower level namely the incomplete Beta function (but in complex domain).

Thank you Jacqueline,
I am trying to calculate the area under the curve but I do not know how to arrange the Gaussian Hypergeometric function or the Beta function.

Can you help me, please? Can you explain the procedure to reach my goal?

For example:
a= 2,43; b= 6; c= 2.5; δ= 9.68 with interval: x1=2.5 and x2=7.5

it is not a question of result, but I would like to understand the porcedure.

Thank you in advance
 
It is possible to compute the numerical value of an hypergeometric function "by hand", thanks to series expansion. But it would be awfully boring and time consuming. That was the way to do it in the good old days, before the age of computers.
If you have "Mathematica" or any other math. package, certainly, the hypergeometric function is included, allowing to compute numerical values.
But the most simple way is to use a numerical integrator. Even some pocket calculator can do that. Just program the function to integrate (no need for hypergeometric function). Also more advanced softwares are very simple to use, for example MatCad (screen copy below)
Some calculators are on free access on the web., for example WolframAlpha (screen copy below), use Google to find them.
 

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JJacquelin said:
It is possible to compute the numerical value of an hypergeometric function "by hand", thanks to series expansion. But it would be awfully boring and time consuming. That was the way to do it in the good old days, before the age of computers.
If you have "Mathematica" or any other math. package, certainly, the hypergeometric function is included, allowing to compute numerical values.
But the most simple way is to use a numerical integrator. Even some pocket calculator can do that. Just program the function to integrate (no need for hypergeometric function). Also more advanced softwares are very simple to use, for example MatCad (screen copy below)
Some calculators are on free access on the web., for example WolframAlpha (screen copy below), use Google to find them.

Thank you Jacquelin!
You solved my doubts, I will use WolframAlpha to calculate the area.
 

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