Prove, or disprove, each of the following: 2n + 9 = O(1) 2^n+3 = O(2^n) 3n^2 + 4n + 5 = O(n^2) n + n times logn = O(n) 2n + 3n^2 + 4n^3 + n times logn = O(nlog(n))