(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

From the Rodrigues’ formulae, I want to derive nature of the spherical Bessel and Neumann functions at small values of p.

2. Relevant equations

I'm going to post an image of the Bessel function where we're using a Taylor expansion, which I'm happy with and is as far as I got...

https://imgur.com/a/LmDovch

3. The attempt at a solution

I'm recovering some of the terms, but the jump from line 1 to 2 and 2 to 3 have me confused because I'm not recovering a similar answer.

I need to attempt it for the Neumann function at small p also, but I'm sure that a similar issue will arise and I'd rather fix it here and use the Neumann as practice for my newfound knowledge

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Derivative of a term within a sum

Have something to add?

**Physics Forums | Science Articles, Homework Help, Discussion**