|
|
Đặt $t=-x$. Ta có
$L=\mathop {\lim }\limits_{x \to 0^-}\dfrac{x-\sqrt{-x}}{\sqrt{\left(-x\right)^3}}=\mathop {\lim }\limits_{t \to 0^+}\dfrac{-t-\sqrt{t}}{\sqrt{t^3}}=\mathop {\lim }\limits_{t \to 0^+}\left ( -\dfrac{1}{\sqrt{t}}-\dfrac{1}{t} \right )=-\infty.$
|