Can someone explain how Big-Oh works with Summations?

Question

I know this isn\'t strictly a programming question, but it is a computer science question so I\'m hoping someone can help me.

I\'ve been working on my Algor

Answer 1

My guess is that what the question statement means is if you're summing the results of some calculation for which the running time is proportional to i² in the first case, and proportional to log₂i in the second case. In both cases, the running time of the overall summation is "dominated" by the larger values of N within the summation, and thus the overall big-O evaluation of both will be N*O(f) where f is the function you're summing.