Access this content offline
Omniguides
Skip to the reading

L’Hospital’s Rule

This original textbook reading covers part of the AP topic. Follow the AP course outline for complete topic instruction and practice.

L’Hospital’s Rule

For any indeterminate limit,

limx→af(x)g(x)=limx→af′(x)g′(x)

Related Glossary Terms

Indeterminate forms

Index

Chapter 5 - L’Hospital’s Rule

Chapter 5 - L’Hospital’s Rule

Glossary and deeper reading · 1 refreshers

These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.

  • L’Hospital’s rule

    L’Hospital’s rule can evaluate certain quotient limits with the indeterminate forms 0/0 or infinity divided by infinity. Its hypotheses require appropriate differentiability near the target, a nonzero denominator derivative there, and a suitable limit of the derivative quotient. For example, lim(x→0) sin x/x equals lim(x→0) cos x/1=1. Differentiating numerator and denominator separately here is a limit theorem, not the quotient rule for derivatives.

    Read more: 4.7 · L’Hospital’s rule →

Search lessons, terms and problems