6. Determine whether or not the following are true and provide a full derivation explaining your answer for each. The domain of the functions of n below is the positive real numbers. For convenience, you may assume that the logs are in the base of your choice, but you should specify what base you are using in your derivation.
(2 marks each)
a. 2n + 4 log n + 3n^2 - 4 is O(n)
b. (21n + 4)^2 is Θ(n^2)
c. 7(n^2 log n) + 5 is O(n^3)
d. n^3 + 7 + 1/n is O(n^3)
e. 3(1 + log n + n log n) is O(n^2)
f. 6n^3 + 5n^4 + 4 log n is Ω(n^3)