Coefficients of a Fourier-Bessel series

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The discussion focuses on the coefficients of a Fourier-Bessel series, specifically the orthogonality relations of Bessel functions. It establishes that for distinct zeroes k_1 and k_2 of J_n(t), the integral of their product over the interval [0, 1] equals zero. Additionally, it presents the integral of the square of a Bessel function, showing that when k_1 equals k_2, the result is half the square of the derivative of the Bessel function at k. The user seeks to evaluate a specific integral involving Bessel functions and suggests that integration by parts may be necessary to derive the results.

PREREQUISITES
  • Understanding of Bessel functions and their properties
  • Familiarity with Fourier-Bessel series
  • Knowledge of Sturm-Liouville problems
  • Proficiency in integral calculus, particularly integration by parts
NEXT STEPS
  • Study the properties of Bessel functions, particularly J_n(t)
  • Learn about Sturm-Liouville theory and its applications to Bessel functions
  • Research integration techniques specific to Bessel functions
  • Examine the paper linked in the discussion for deeper insights on evaluating integrals involving Bessel functions
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Mathematicians, physicists, and engineers working with Fourier-Bessel series, particularly those involved in solving problems related to Bessel functions and orthogonality relations.

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When finding the coefficients of a Fourier-Bessel series, the Bessel functions satisfies, for k_1and k_2 both zeroes of J_n(t), the orthogonality relation given by:
$$\int_0^1 J_n(k_1r)J_n(k_2r)rdr = 0, (k_1≠k_2)$$
and for k_1 = k_2 = k:

$$\int_0^1 J_n^2(kr)rdr = \frac12J_n^{'2}(k)$$

I understand how to get the first result since the Bessel's equation can be interpreted as a Sturm-Liouville problem, but how can I show the second one?
 
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This paper might offer a clue:
 

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SteamKing said:
This paper might offer a clue:

But how exactly i can evaluate the integral and get the result given by: I = \frac{R^2}{\alpha_m^2 - \alpha_n^2}[\alpha_mJ_0(\alpha_n)J_1(\alpha_m) - \alpha_nJ_0(\alpha_m)J_1(\alpha_n)] or another more general formula for Bessel functions of different order?
 
I believe an integration by parts is called for, using certain relations of Bessel functions to get over the tricky bits:

http://home.comcast.net/~rmorelli146/U3150/Bessel.pdf
 
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