ε
Epsilon in Mathematics
In Mathematics, the Epsilon symbol (ε) is commonly used. Learn how to copy and use it in your technical documents.
Unicode
U+03B5
HTML Entity
ε
LaTeX Sequence
\epsilon
Primary Field
MathematicsMathematics Application
Epsilon stands for an arbitrarily small positive quantity — central to the epsilon–delta definition of limits in calculus. It also denotes permittivity in electromagnetism, strain in mechanics, and the error term in statistical models.
How to type Epsilon (ε)
- Fastest: click ε on the keyboard above — it copies to your clipboard, ready to paste into Word, Google Docs, email or a forum.
- Unicode: the code point is shown in the panel above; on Windows you can also use Alt‑X after the hex code in Word.
- LaTeX: use the command shown above inside math mode.
- Anywhere: because it’s standard Unicode, it keeps its exact form across apps and devices.
Frequently asked questions
What does ‘epsilon’ mean in limits?
It represents an arbitrarily small positive distance; the epsilon–delta definition formalizes what it means for a function to approach a limit.
Is ε used in electronics?
Yes — permittivity (ε) describes how a material responds to an electric field, key to capacitor design.
Write mathematical and scientific expressions
Need to pair this symbol with other operators?