Calculus Limit Guide & Step-by-Step Rules
Learn fundamental methods for evaluating one-sided, two-sided, and infinite limits.
1. Direct Substitution
The first rule of limit evaluation is direct substitution. If f(x) is continuous at x = c, then limit equals f(c).
2. Resolving Indeterminate Forms
When direct substitution yields an indeterminate form like 0/0 or inf/inf, try algebraic techniques:
- Factoring: Factor numerator and denominator to cancel common zero-factors.
- Conjugate Rationalization: For radical expressions, multiply numerator and denominator by conjugate.
- L'Hôpital's Rule: Apply derivatives to numerator and denominator.