What is the domain of f(x)=9−x2+x2−1f(x) = \sqrt{9-x^2} + \sqrt{x^2-1}f(x)=9−x2+x2−1?
[−3,3][-3, 3][−3,3]
[−3,−1]∪[1,3][-3, -1] \cup [1, 3][−3,−1]∪[1,3]
[1,3][1, 3][1,3]
x∈Rx \in \mathbb{R}x∈R