Calculus II, Lecture 8: L'Hospital's rule

Lecture 8: L'Hospital's rule.

When computing the limit of a function as x goes to a, the first thing to do is plug in x=a and see if it's defined. Sometimes this yields an "indeterminate" such as 0/0, or infinity/infinity. In this case, we can use L'Hospital's rule to evaluate the limit: take the derivative of the numerator and denominator, and then try again.