In fact, I could say from:
divided by (i don't know how to do division using this formatting!)
But inserting this into the identity gives a fairly trivial result and I don't think that's what the question is after...?
I am trying to find the missing factor here:
I have tried various things. First I tried to do it by construction, giving:
where b is such that:
But I can't find such a b.
Then I tried to do it by long division of polynomials but because the exponent is n and not a given value, this got very messy and I couldn't get it work.
Can someone help me out?