Data Structures, Algorithms, & Applications in C++
Chapter 2, Exercise 11

(a)
f(n) / g(n) = 10n + 9 / n which goes to infinity as n goes to infinity. So, f(n) is not O(g(n)).

(c)
g(n) / f(n) = log n which goes to infinity as n goes to infinity. So, f(n) is not Theta(g(n)).