L'Hôpital's Rule
If:
$$\lim_{x\to a}\frac{f(x)}{g(x)}$$
gives an indeterminate form $$\frac{0}{0}$$ or $$\frac{\infty}{\infty}$$, and the required conditions are satisfied, then:
$$\lim_{x\to a}\frac{f(x)}{g(x)}=\lim_{x\to a}\frac{f'(x)}{g'(x)}$$
provided the limit on the right exists.
Usage
- Used to evaluate difficult quotient limits producing $$\frac{0}{0}$$ or $$\frac{\infty}{\infty}$$.