Chapter 13 - A Preview of Calculus: The Limit, Derivative, and Integral of a Function - Section 13.3 One-sided Limits; Continuous Functions - 13.3 Assess Your Understanding - Page 909: 40

$2$

We find the left-hand limit as follows: $\lim\limits_{x \to 1^{-}} f(x)=\lim\limits_{x \to 1^{-}} \dfrac{x^3-x}{x-1} \\=\lim\limits_{x \to 1^{-}} \dfrac{x(x-1)(x+1)}{x-1} \\=\lim\limits_{x \to 1^{-}} \ x (x+1) \\=(1)(1+1) \\=2$