# Beta (Βήτα)

**Beta** (Βήτα; uppercase Β, lowercase β) is the second letter of the [Greek alphabet](https://www.edgepedia.org/greek-alphabet).<sup>[1](https://www.mathwords.com/b/beta.htm)</sup> In Modern Greek it is spelled βήτα in monotonic orthography and pronounced ˈvita, with the letter representing the sound v.<sup>[2](https://graphsearch.epfl.ch/en/concept/166771)</sup> Together with alpha it supplies the name of the alphabet itself, and its lowercase form is widely used in mathematics, statistics, physics, and finance.

| Key fact | Detail |
|---|---|
| Position and forms | Second letter of the Greek alphabet; uppercase Β, lowercase β<sup>[1](https://www.mathwords.com/b/beta.htm)</sup> |
| Modern pronunciation | βήτα pronounced ˈvita in Modern Greek, a v sound<sup>[2](https://graphsearch.epfl.ch/en/concept/166771)</sup> |
| Origin | Name adopted from the acrophonic name of the Phoenician letter, the common Semitic word *bait, meaning "house"<sup>[2](https://graphsearch.epfl.ch/en/concept/166771)</sup> |
| English word | "Beta" recorded in English c. 1300, from Greek, from Hebrew/Phoenician beth<sup>[3](https://www.etymonline.com/word/beta)</sup> |
| Alphabet name | The names of the first two signs, Hebrew ʼālep and bêt (Greek alpha and beta), form the basis of the word "alphabet"<sup>[4](https://www.metmuseum.org/exhibitions/listings/2014/assyria-to-iberia/blog/posts/alphabet)</sup> |
| Unicode | Β at U+0392, β at U+03B2, and the curled beta symbol ϐ at U+03D0<sup>[5](https://unicode.org/charts/PDF/U0370.pdf)</sup> |

## Origin and transmission

Along with the other letters, this one passed from Phoenician hands to the Greeks and Etruscans, and later reached the Romans.<sup>[4](https://www.metmuseum.org/exhibitions/listings/2014/assyria-to-iberia/blog/posts/alphabet)</sup> As with most other Greek letter names, beta's name comes from the acrophonic designation of the matching Phoenician letter, which was the common Semitic word *bait, meaning "house".<sup>[2](https://graphsearch.epfl.ch/en/concept/166771)</sup> Greece.com similarly notes that "Beta" is supposed to be the picture of a house, and that beta has the same ancestors as "Beth", Hebrew for "house".<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup> The English word beta itself entered the language around 1300 through Greek, from the Hebrew or Phoenician beth.<sup>[3](https://www.etymonline.com/word/beta)</sup>

## Pronunciation in Modern Greek

The letter has two principal English pronunciations, UK /ˈbiːtə/ and US /ˈbeɪtə/, while the Greek name is βήτα, pronounced ˈvita in [Modern Greek](https://www.edgepedia.org/modern-greek).<sup>[2](https://graphsearch.epfl.ch/en/concept/166771)</sup> A Greek language reference describes the modern sound as v, as in vase.<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>

## Uses in mathematics and science

The lowercase β is the workhorse form. Documented uses include:<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>

- the second angle in a triangle<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- one root of a quadratic equation, where α represents the other<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- the ratio of collector current to base current in a bipolar junction transistor in electronics<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- the false negative rate in statistics<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- the beta coefficient, the non-diversifiable risk, of an asset in mathematical finance<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- the sideslip angle of an airplane<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- the first-order effects of variations in the [Coriolis force](https://www.edgepedia.org/coriolis-force) with latitude in planetary dynamics<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- a beta particle, an emitted electron<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>
- sound intensity<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>

Mathwords adds the slope coefficient in a linear regression model, the second parameter of the beta probability distribution, and the Type II error rate in hypothesis testing as standard uses of β.<sup>[1](https://www.mathwords.com/b/beta.htm)</sup> In the simple linear regression model,
\[ \hat{y} = \beta_0 + \beta_1 x \]
where \( \beta_0 \) is the y-intercept, the predicted value when x = 0, and \( \beta_1 \) is the slope coefficient, the change in the predicted value per unit change in x.<sup>[1](https://www.mathwords.com/b/beta.htm)</sup> The uppercase Β is rarely used in mathematical writing because it is visually identical to the Latin letter B.<sup>[1](https://www.mathwords.com/b/beta.htm)</sup> The uppercase also stands for the beta function in mathematics.<sup>[6](https://www.greece.com/info/language/greek_alphabet/Beta/)</sup>

## Encoding

Unicode encodes the capital as U+0392 GREEK CAPITAL LETTER BETA and the small letter as U+03B2 GREEK SMALL LETTER BETA, in the Greek and Coptic block (range 0370–03FF).<sup>[5](https://unicode.org/charts/PDF/U0370.pdf)</sup><sup> • </sup><sup>[7](https://www.w3.org/Math/characters/html/symbol.html)</sup> A separate character, U+03D0 GREEK BETA SYMBOL, encodes the curled variant ϐ, approximately equal in appearance to the small letter β; Unicode's variation-sequence mechanism likewise distinguishes particular beta glyph forms needed for mathematics from the free letterform used in ordinary Greek text.<sup>[5](https://unicode.org/charts/PDF/U0370.pdf)</sup><sup> • </sup><sup>[8](https://www.unicode.org/faq/vs.html)</sup> The character charts also list related Latin letters derived from or resembling the form, including ƀ (latin small letter b with stroke) and the latin small letter beta ꞵ.<sup>[5](https://unicode.org/charts/PDF/U0370.pdf)</sup>

## References

1. [Beta (β) — Greek Letter Meaning & Uses in Math, Mathwords](https://www.mathwords.com/b/beta.htm)
2. [Beta, EPFL Graph Search](https://graphsearch.epfl.ch/en/concept/166771)
3. [Beta - Etymology, Origin & Meaning, Etymonline](https://www.etymonline.com/word/beta)
4. [Alphabet Origins: From Kipling to Sinai, The Metropolitan Museum of Art](https://www.metmuseum.org/exhibitions/listings/2014/assyria-to-iberia/blog/posts/alphabet)
5. [The Unicode Standard, Greek and Coptic chart (U+0370)](https://unicode.org/charts/PDF/U0370.pdf)
6. [Greek Letter Beta | Βήτα - Β, Greece.com](https://www.greece.com/info/language/greek_alphabet/Beta/)
7. [SYMBOL Characters and Glyphs, W3C Math](https://www.w3.org/Math/characters/html/symbol.html)
8. [FAQ - Variation Sequences, Unicode Consortium](https://www.unicode.org/faq/vs.html)

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*Topic: Encyclopedia › Society and history › Languages and linguistics › Writing and notation systems › Mediterranean, Italic, and undeciphered ancient scripts*

*Initially written Sep 17, 2026 · Reviewed: Sep 18, 2026; Sep 30, 2026; Oct 25, 2026 · Edited: Sep 18, 2026; Sep 30, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*

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