Question

what is the domain of f(x)=cos(x)? A. the set of real numbers -2pi ≤ x ≤ 2pi B. the set of real numbers -1≤x≤1 C. the set of real numbers 0≤x≤2pi D. the set of all real numbers

Answer 1

The domain for cosine is all real numbers because you can go around the unit circle forever and stop at any point on the circle.

Answer: D

Answer 2

Answer: D. the set of all real numbers

Explanation:

The domain of cos x and sine x are set of real numbers , that is the domain is

{-∞ , +∞}