The domain of the function $f(x)= log (x^2-4)$ is :

[2, ∞) (-∞, -2) ∪ (2, ∞) (2, ∞) (-∞, -2] ∪ (-2, -1)

(-∞, -2) ∪ (2, ∞)

The correct answer is Option (2) → $(-∞, -2) ∪ (2, ∞)$ $f(x)= \log (x^2-4)$ $(x^2-4)>0⇒(x-2)(x+2)>0$ using wavy curve method $x∈(-∞, -2) ∪ (2, ∞)$