To illustrate intuitively the concept of limit.[br][br]Observations: [br]1. As the points [math]x[/math] move toward [math]a=1[/math], the values of [math]\frac{x^2-1}{x-1}[/math] tend to 2.[br]2. The function [math]\frac{x^2-1}{x-1}[/math] is [b]not[/b] defined at [math]x=1[/math].