Question

Mostre, usando a definição de limites, que \underset{x\rightarrow3}{lim}\;\frac{x^2-9}{x-3}=6

Answer 1

$\underset{x\rightarrow3}{lim}\;\frac{x^2-9}{x-3}= \underset{x\to3}{lim} \frac{(x+3)(x-3)}{x-3}= \underset{x\to3}{lim}x+3=3+3=\boxed{6}$