Is this going to be one of those threads where we have to drag it out of you to figure out what you've done?
More generally, this is showing where your plan of getting through a graduate program in physics on your own, in an order of magnitude faster time than physics graduate students breaks down. It's not enough to have seen the prerequisites - you need to know it. On July 24th you were complaining about the first chapter in Boas. On November 12th, you were saying you were nearly done with it. That's very fast, You also said you weren't working through all the problems, and now you are faced with a problem you can't solve because you don't have the math background. Whizzing through a text at lightning speed avoiding the problems isn't going to get you the math.
Well, this isn't a exercise of the book, but a section of the book trying to explain the method, i didn't anything, and my question is HOW he managed to apply these boundary conditions to the radial green function and get these equations below, and other thing, i was complaining about Boas book because the first chapter is REALLY boring, but i managed to understand almost everything in this chapter, the other chapters are VERY fluid and i was having fun with it,and i make a pause in chapter 10 of the book, and another thing, this is a community, where everyone help the others, if you don't wanna help just don't post, if you want to indicate a problem in my study plan or even advise a book to reinforce my knowledge, great, i would love this, but come here in a public post and talk like that..., it's ok if you don't want to help, but there's no reason to humiliate me that way.