Chapter 1.6, Problem 10E

Determine $\underset{x\to 1^{-}}{\lim }\frac{1}{x^3-1}$ and $\underset{x\to 1^{+}}{\lim }\frac{1}{x^3-1}$

1. (a) by evaluating f (x) = 1/(x³ − 1) for values of that approach 1 from the left and from the right,
2. (b) by reasoning as in Example 1, and
3. (c) from a graph of f.