Limits: getting close to a number

Fill in a table of values close to a point where a function is undefined, read the limit from the graph, and see why the left-hand and right-hand limits must agree.

Guide

A limit asks: as x gets close to a number (without reaching it), which number does f(x) get close to? It is not the same as the value of the function at that point; the function may not even be defined there.

You can approach from two sides: from the left (the left-hand limit) and from the right (the right-hand limit). If both reach the same number, that number is the limit. If they differ, the limit does not exist.