Hypergeometric identity proof using Pochhammer

awebs4
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I'm trying to show that:

F(a, b; z) = F(a-1, b; z) + (z/b) F(a, b+1 ; z)


where F(a, b; z) is Kummer's confluent hypergeometric function and
F(a, b; z) = SUMn=0[ (a)n * z^n ] / [ (b)n * n!]

where (a)n is the Pochhammer symbol and is defined by:
a(a+1)(a+2)(a+3)...(a+n-1)

some Pochhammer identities include:
a(a+1)n = (a+n)(a)n = (a)n+1



The Attempt at a Solution


my attempt includes pages of scrap that would be heinous to type out. i started on the right hand side of the equation and got it to look like:

[ (a-1)/(a+n-1) + z/(b+n) ] * F(a, b; z)

hoping that whatever was left after factoring out a F(a, b; z) would equal 1, but i can't get it to go away.


asking on here is really my last resort because I've spent so much time on this and it's due soon... so if someone's out there and can possibly help me, i hope you do it quickly. even if you help after it's due, i'd still like to know how it's done.
 
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nevermind i got it to work out
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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