Question

If f(x) = x^2 + 4 then range of f(x) is given by?

(a) [4, ∞)

(b) (-∞, ∞) – {0}

(c) (0, ∞)

(d) None of the mentioned

This question was addressed to me during an online exam.

I'd like to ask this question from Domain and Range of Functions in section Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

Right option is (a) [4, ∞)

To explain: Since minimum value of x^2 is 0, thus x^2 +4 may take any value between [4,∞).