For Big-O notation in mathematics,
How does $f(n) = 2n^2 + 3n + 1 = O(n^2)$?
Does it require any more information for the proof?
Edit:
c ≥6 ≥3 * 3/4 ≥3 * 1/9 ----> 2 -------------------------------------------------------------- N 1 2 3 ----> ∞