Whitman College: David Guichard's "Calculus, Chapter 4: Transcendental Functions, Section 4.10: Limits Revisited"
Read Section 4.10 (pages 94-97). You will learn how derivatives relate back to limits. Limits of Indeterminate Forms (or limits of functions that, when evaluated, tend to 0/0 or ∞/∞) have previously been beyond our grasp. Using L'Hopital's Rule, you will find that these limits are attainable with derivatives.