One-Sided Limits

A one-sided limit describes how a function behaves as the input approaches a point from only one direction—either from the left or from the right. This section focuses on observing directional behavior using graphs and values, and on understanding why approaching from different sides can lead to different outcomes. One-sided limits help explain jumps, boundaries, and points where a function changes behavior.

Estimated

15-20 min.

Difficulty

Intermediate

Key Concepts

  • Left-Hand Limit
  • Right-Hand Limit
  • Directional Behavior
  • Boundary Points

A one-sided limit describes how a function behaves as the input approaches a particular value from only one direction—either from values smaller than that number or from values larger than it. Instead of looking at what happens exactly at the point, we observe how the function’s outputs behave as we move closer and closer from one side. This idea is especially important when a function changes behavior at a point, such as when there is a jump, a boundary, or a sharp transition. By examining each direction separately, we can determine whether the function approaches the same value from both sides or behaves differently depending on the direction of approach.

Video Lesson