What does epsilon represent in math?

Answer 1

• In mathematics (in particular calculus), an arbitrarily small positive quantity is commonly denoted ε; see (ε, δ)-definition of limit
• In mathematics, Hilbert introduced epsilon terms as an extension to first order logic; see epsilon calculus.
• In mathematics, the Levi-Civita symbol.
• In mathematics, to represent the dual numbers: a + bε, with ε2 = 0 and ε ≠ 0.
• In mathematics, sometimes used to denote the Heaviside step function.