Question

If f1(x) is O(g(x)) and f2(x) is o(g(x)), then f1(x) + f2(x) is?

(a) O(g(x))

(b) o(g(x))

(c) O(g(x)) + o(g(x))

(d) None of the mentioned

This question was addressed to me in an online quiz.

This interesting question is from The Growth of Functions in chapter Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

Correct option is (a) O(g(x))

Explanation: f2(x) is less than O(g(x)). So, f1(x) + f2(x) upper bound is  O(g(x)).