Question

Помогите найти предел
$\lim_{x \to \ 4} \sqrt{2x(x-4)}/ x-4$

Answer 1

$lim_{x\to 4}\frac{\sqrt{2x(x-4)}}{x-4}=lim_{x\to 4}\frac{\sqrt{2x}}{\sqrt{x-4}}=[\, \frac{\sqrt{2\cdot 4}}{\sqrt{4-4}}=\frac{2\sqrt2}{0}\, ]=\infty$