• + 2 comments

    Isn't that a little overcomplicated?

    S_n = (n^2 - (n-1)^2) + ((n-1)^2 - (n-2)^2) + ... + (1 - 0)

    The only terms in this sum that don't cancel are the first and last: n^2 and 0.

    Partial sums arrive at the same answer but I think the above logic is what the question is contructed around.