Summary of the Limit Laws

Essential Concepts

  • The limit laws allow us to evaluate limits of functions without having to go through step-by-step processes each time.
  • For polynomials and rational functions, limxaf(x)=f(a)limxaf(x)=f(a).
  • You can evaluate the limit of a function by factoring and canceling, by multiplying by a conjugate, or by simplifying a complex fraction.
  • The Squeeze Theorem allows you to find the limit of a function if the function is always greater than one function and less than another function with limits that are known.

Key Equations

  • Basic Limit Results
    limxax=alimxax=a
    limxac=climxac=c
  • Important Limits
    limθ0sinθ=0limθ0sinθ=0
    limθ0cosθ=1limθ0cosθ=1
    limθ0sinθθ=1limθ0sinθθ=1
    limθ01cosθθ=0limθ01cosθθ=0

Glossary

infinite limit
A function has an infinite limit at a point aa if it either increases or decreases without bound as it approaches aa
intuitive definition of the limit
If all values of the function f(x)f(x) approach the real number LL as the values of x(a)x(a) approach aa, f(x)f(x) approaches LL
one-sided limit
A one-sided limit of a function is a limit taken from either the left or the right
vertical asymptote
A function has a vertical asymptote at x=ax=a if the limit as xx approaches aa from the right or left is infinite