can anybody share on me how to find the nth term of a binomial expansion / theorem with the negative exponet
(x+y)^-2,, find the 9th term.. how is it possible?
I don't think what you're looking for exists.
There is this: For .
So if , then , where (Note ).
You could expand that out, giving:
And then collect all like terms - if it even converges term-wise when you try that (I don't know), much less converges to the original value. So, you could maybe give this approach a whirl - no guarantees from me that it gets you anywhere though. And it puts you in a world of series and convergence - a bit different than the nice formula for the binomial coefficients. I don't think the thing you want exists.