What the app does
At every edge — a hole punched out of the domain, a finite endpoint, and ±∞ if the domain reaches that far — the function is evaluated at points closing in on the boundary and the trend is classified: settling on a value, running away to infinity, or doing neither.
Why it matters
Limits are what turn a list of points into a shape. They say whether the curve shoots off near a hole, flattens towards a level, or quietly closes a gap — as sin(x)/x does at 0, where the function is undefined but the limit is 1.
Read further
- Limit of a function Wikipedia
- One-sided limit Wikipedia
- One-sided limits Paul's Online Notes