I want to say thank you to plato because I think I an understand what the book is asking. This problem asks to find a formula in terms of n for the sum where the lower limit in sigma notation is k=1 the upper limit=n and k=sum of the integers. So I was thinking that the lower limit is k=1 and the upper limit is n then the sum of the integers K = n(n+1)/2, is this correct? and is the identity of this formula: (n+1)^3-1^3 ?
Please let me know if I am on the right track, I would appreciate any feedback you could give me.