\varepsilonThe Greek letter \varepsilon is often used in mathematics and science to represent a small positive quantity, an error term, or a tolerance level. It is a variant of the Greek letter epsilon and is commonly used in calculus, analysis, and other fields to denote an arbitrarily small positive number.
Represents a small positive number in calculus or analysis.
0 < \varepsilon < 1Used in the definition of limits to indicate that x is within an epsilon distance from a.
|x - a| < \varepsilonIndicates that the function f(x) is within an epsilon range of L.
f(x) = L \pm \varepsilon