The domain of definition of the function $y=3e^{\sqrt{x^2-1}}\log(x-1)$ is

(1, ∞) [1, ∞) set of all reals different from 1 (-∞, -1) ∪ (1, ∞)

(1, ∞)

For $D_f,x^2-1≥0$ and x - 1 > 0 ⇒ |x| ≥ 1 and x > 1 ⇒ x > 1 $⇒ D_f= (1, ∞)$