Find the mistake in the following argument:
We show that 12 + 22 + 32 + ... + n? is big-O of n2.
Since i? ≤ n? for i = 1,2...n, each term in the sum 12 + 22 + 32+... +n?
is less than or equal to n'. Thus, the maximum of the big-O estimates
of each term is n?, which implies that the sum 12 + 22 + 32 + ... + n° is
big-O of n?.