1000 Problems in Calculus (Problem 2)

Problem 2:
Find the domain of \dfrac{1}{\sqrt{x^2-1}}.

Since we have x^2-1 under the square root and on denominator, x^2-1> 0 , it means that x> 1 or x< -1 , so the domain is (-\infty,-1) \cup (1, \infty) .

See problem 1 and Problem 3.