Put each of the bracketed terms over a common denominator and simplify a bit. That will leave you with a series you should recognise and be able to sum.
Put each of the bracketed terms over a common denominator and simplify a bit. That will leave you with a series you should recognise and be able to sum.
RonL
i tried that and ended up with . but i can't remember for the life of me how to sum something like that...
No the lower limit of summation should have been 0, and now is (it is just a constant term that
disappears on differentiation, or sometimes when just typing).