GreekSymbol
Sigma
The eighteenth letter of the Greek alphabet, central to summation, statistics, and several physical quantities.
What it means
Description
The eighteenth letter of the Greek alphabet, central to summation, statistics, and several physical quantities.
Derived from the Phoenician letter 'Shin'.
In mathematics
Mathematical Usage
- Summation operator (Σ)
- Standard deviation (σ)
- Permutation-related notation
- Special functions in some texts
In science
Scientific Usage
- Stress
- Conductivity
- Stefan-Boltzmann constant
- Sigma bonds in chemistry
Did you know?
Interesting Fact
Sigma has two lowercase written forms in Greek: σ in general use and ς at the end of a word.