HTML | Meaning | |
---|---|---|

Σ |
`Σ` `Σ` `U+3A3` |
Sigma Symbol (Uppercase)The uppercase Sigma is used in mathematics to denote the sum of a series of terms. |

σ |
`σ` `σ` `U+3C3` |
Sigma Symbol (Lowercase)The lowercase sigma symbol is often used in mathematics to represent standard deviation in statistics and the sum of a series. |

ς |
`ς` `ς` `U+3C2` |
Final SigmaThe final sigma is used in Greek writing as the last letter in a word. |

∑ |
`∑` `∑` `U+2211` |
Summation SymbolThis symbol is often used in mathematics to represent the sum of a sequence of terms, similar to the uppercase Sigma. |

π |
`π` `π` `U+3C0` |
Pi SymbolOften appears in mathematical equations along with Sigma. |

α |
`α` `α` `U+3B1` |
Alpha SymbolUsed in various scientific formulas, sometimes in conjunction with Sigma. |

β |
`β` `β` `U+3B2` |
Beta SymbolFrequently used along with Sigma in mathematical and scientific equations. |

γ |
`γ` `γ` `U+3B3` |
Gamma SymbolUsed to represent the Euler–Mascheroni constant among other things. |

δ |
`δ` `δ` `U+3B4` |
Delta SymbolRepresents change in mathematics and science. |

∞ |
`∞` `∞` `U+221E` |
Infinity SymbolRepresents the concept of something being infinite or unbounded. |

### What is the Sigma Symbol?

The Sigma symbol, denoted as σ (lowercase), Σ (uppercase), and ς (final), is part of the Greek alphabet where it serves as the eighteenth letter. Additionally, the Lunate Sigma (Ϲ for uppercase, ϲ for lowercase) is a variant form of the Sigma symbol. It is widely used in mathematics and statistics, as well as in other scientific disciplines. The symbol has its origins in ancient Greek culture and has evolved to serve various purposes in modern studies.

### Original and Variations of the Sigma Symbol

The Sigma symbol has an original form as well as several variations. Below are these forms, presented in plain text for easy copying and pasting:

**Original Symbols:**`σ`

,`Σ`

,`ς`

**Variations:**`∑`

,`𝚺`

,`𝛔`

,`𝛓`

,`𝛴`

,`𝜎`

,`𝜍`

,`𝜮`

,`𝝈`

,`𝝇`

,`𝝨`

,`𝞂`

,`𝞁`

,`𝞢`

,`𝞼`

,`𝞻`

### Applications of the Sigma Symbol in Various Fields

The Sigma symbol has different applications depending on its form. These applications span multiple disciplines:

**Mathematics:**Σ is primarily used to represent the sum of a series of terms. σ is commonly used to indicate standard deviation in statistics.**Physics:**σ is used to denote electrical conductivity. Σ is less commonly used but may appear in certain contexts like summations.**Computer Science:**Σ may be employed in algorithmic notations and complexity theory. σ is less commonly used.**Engineering:**σ commonly represents stress in materials. Σ can represent the sum of forces or other summations.**Biology:**σ can signify specific families of proteins or receptors. Σ is less commonly used in biology.**Chemistry:**σ is often used to represent reaction rates or sigma bonds in molecules. Σ is rarely used in chemistry.

### How to Type the Sigma Symbol Using Keyboard Shortcuts, Alt Codes, and LaTeX

**Windows:**Hold down the`Alt`key and type`228`

(for lowercase σ),`931`

(for uppercase Σ), or`962`

(for final sigma ς) on the numeric keypad, then release the`Alt`key.**Mac:**For all types of sigma, it's often necessary to use a special character menu or copy them from elsewhere.**Linux:**Press`Ctrl`+`Shift`+`u`, then type`03c3`

(for lowercase σ),`03a3`

(for uppercase Σ), or`03c2`

(for final sigma ς) and press`Enter`.**HTML:**For lowercase σ, use`σ`

; for uppercase Σ, use`Σ`

; and for final sigma ς, use`ς`

.**LaTeX:**For lowercase σ, use the command`\sigma`

; for uppercase Σ, simply type`\Sigma`

; and for final sigma ς, use`\varsigma`

.