# Greek letters used in mathematics

Greek alphabet
Α α AlphaΒ β Beta
Γ γ GammaΔ δ Delta
Ε ε EpsilonΖ ζ Zeta
Η η EtaΘ θ Theta
Ι ι IotaΚ κ Kappa
Λ λ LambdaΜ μ Mu
Ν ν NuΞ ξ Xi
Ο ο OmicronΠ π Pi
Ρ ρ RhoΣ σ Sigma
Τ τ TauΥ υ Upsilon
Φ φ PhiΧ χ Chi
Ψ ψ PsiΩ ω Omega
obsolete letters
Ϝ ϝ Digamma San
Ϙ ϙ QoppaϠ ϡ Sampi
Greek letters are used in mathematics, science, engineering, and other areas where mathematical notation is used as symbols for constants, special functions, and also conventionally for variables representing certain quantities. In these contexts, the capital letters and the small letters represent distinct and unrelated entities. Those Greek letters which have the same form as Latin letters are usually not used: capital A, B, E, H, I, K, M, N, O, P, T, X, Y, Z; small o. Small ι (iota) and υ (upsilon) are also rarely used, since they closely resemble the Latin letters i and u. Sometimes font variants of Greek letters are used as distinct symbols in mathematics, in particular for phi and pi.

In mathematical finance, The Greeks are the variables denoted by Greek letters used to describe the risk of certain investments.

English-speaking mathematicians use neither the modern nor the historical Greek pronunciations of the names of the letters, but the traditional English pronunciation, e.g. [ˈθeɪtʌ] for θ cf. ancient [tʰɛ̂ːta] and modern [ˈθita].

## Typography

The Greek letter forms used in mathematics are often different from those used in Greek-language text: they are designed to be used in isolation, not connected to other letters, and some use variant forms which are not normally used in current Greek typography.

The OpenType font format has the feature tag 'mgrk' "Mathematical Greek" to identify a glyph as representing a Greek letter to be used in mathematical (as opposed to Greek language) contexts.

The table below shows a comparison of Greek letters rendered in TeX and HTML. The font used in the TeX rendering is an italic style. This is in line with the convention that variables should be italicized. As Greek letters are more often than not used as variables in mathematical formulas, a Greek letter appearing similar to the TeX rendering is more likely to be encountered in works involving mathematics.

Greek Letters
Name TeX HTML Name TeX HTML Name TeX HTML Name TeX HTML Name TeX HTML
BetaΒßZetaΖ?LambdaΛ?PiΠpPhiΦf
GammaΓ?EtaΗ?MuΜµRhoΡ?ChiΧ?
DeltaΔdThetaΘ?NuΝ?SigmaΣsPsiΨ?
EpsilonΕeIotaΙ?XiΞ?TauΤtOmegaΩ?

## Concepts represented by a Greek letter

#### Ϝ (Digamma)

• Ϝ is sometimes used to represent the Digamma function, though the Latin letter F (which is nearly identical) is normally substituted.

#### Οο (Omicron)

• Ο represents:
• big O notation (may be represented by an uppercase Latin O as well)

#### Υυ (Upsilon)

• Y represents:
• an elementary particle

#### Ωω (Omega)

Greek alphabet
Child systems Gothic
Glagolitic
Cyrillic
Coptic
Old Italic alphabet
Latin alphabet

ISO 15924 Grek

Alpha (Greek ἄλφα), (uppercase Α, lowercase α) is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter Aleph .
Beta (uppercase Β, lowercase β and internal ϐ) is the second letter of the Greek alphabet. In the system of Greek numerals it has a value of 2. It was derived from the Phoenician letter Beth .
Gamma (uppercase Γ, lowercase γ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. It was derived from the Phoenician letter Gimel .
Delta (uppercase Δ, lowercase δ) is the fourth letter of the Greek alphabet. In the system of Greek numerals it has a value of 4. It was derived from the Phoenician letter Dalet .
Epsilon (uppercase Ε, lowercase ε) is the fifth letter of the Greek alphabet, corresponding phonetically to a close-mid front unrounded vowel /e/. In the system of Greek numerals it has a value of 5. It was derived from the Phoenician letter He .
Zeta (uppercase Ζ, lowercase ζ) is the sixth letter of the Greek alphabet. In the system of Greek numerals it has a value of 7. It was derived from the Phoenician letter Zayin . Letters that arose from Zeta include the Roman Z and Cyrillic З (Ze).
Eta (uppercase Η, lowercase η) is the seventh letter of the Greek alphabet. In the system of Greek numerals it has a value of 8. It was derived from the Phoenician letter Heth . Letters that arose from Eta include the Latin H and the Cyrillic letter И.
Theta (uppercase Θ, lowercase θ or ϑ) is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth. In the system of Greek numerals it has a value of 9.

Kappa (uppercase Κ, lowercase κ or ϰ) is the 10th letter of the Greek alphabet, used to represent the voiceless velar stop, or "k", sound in Ancient and Modern Greek.
Lambda (uppercase Λ, lowercase λ) is the 11th letter of the Greek alphabet. In the system of Greek numerals it has a value of 30. Letters that arose from Lambda include the Roman L and the Cyrillic letter El (Л, л).
Mu (uppercase Μ, lowercase μ) is the 12th letter of the Greek alphabet. In the system of Greek numerals it has a value of 40. Mu was derived from the Egyptian hieroglyphic symbol for water () which had been simplified by the Phoenicians and named after their
Nu (uppercase Ν, lowercase ν) is the 13th letter of the Greek alphabet. In the system of Greek numerals it has a value of 50. Its Latin Alphabet equivalent is N.
Xi (uppercase Ξ, lowercase ξ) is the 14th letter of the Greek alphabet. It is pronounced [zaɪ] by US English speakers, but [ksi]
Omicron (uppercase Ο, lowercase ο, literally "small o": o mikron, micron meaning 'small' in contrast to omega) is the 15th letter of the Greek alphabet. In the system of Greek numerals it has a value of 70.
Pi (uppercase Π, lower case π) is the sixteenth letter of the Greek alphabet. In the system of Greek numerals it has a value of 80.

In Modern Greek, the name of the letter is pronounced /pi/
Rho (uppercase Ρ, lowercase ρ or ϱ) is the 17th letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Semitic Rêš "head" (see Resh).
Sigma (upper case Σ, lower case σ, lower case in word-final position ς) is the eighteenth letter of the Greek alphabet. In the system of Greek numerals it has a value of 200.
Tau (uppercase Τ, lowercase τ) is the 19th letter of the Greek alphabet. In the system of Greek numerals it has a value of 300. This letter in English is pronounced taʊ
Upsilon (uppercase Υ, lowercase υ) is the 20th letter of the Greek alphabet. In the system of Greek numerals it has a value of 400. It is derived from the Phoenician waw.
Phi (uppercase Φ, lowercase φ or ϕ), pronounced [fi] in modern Greek and as [faɪ] in English, is the 21st letter of the Greek alphabet.
Chi (uppercase Χ, lowercase χ) is the 22nd letter of the Greek alphabet. Its value in Ancient Greek was an aspirated velar stop /kʰ/ (in the Western Greek alphabet: /ks/).
Psi (uppercase Ψ, lowercase ψ) is the 23rd letter of the Greek alphabet and has a numeric value of 700. In both Classical and Modern Greek, the letter indicates the combination /ps/ (like in English "lapse").
OMEGA is the premier counter-terrorism unit of Latvia.

Founded in 1992, OMEGA cooperates with many other counter-terrorism units over the world. Its equipment and weaponry includes the Heckler & Koch MP5, the Steyr AUG and the Makarov PM.
Digamma (uppercase Ϝ, lowercase ϝ) is an archaic letter of the Greek alphabet, used primarily as a Greek numeral.

The letter had the phonetic value of a voiced labial-velar approximant /w/.
San (uppercase Ϻ, lowercase ϻ) was a letter of the Greek alphabet, appearing between Pi and Qoppa in alphabetical order, corresponding in position to the Phoenician Tsade , but its name comes from Shin.
Qoppa or Koppa (uppercase Ϙ, lowercase ϙ) is a letter that was used in early forms of the Greek alphabet, derived from Phoenician qoph.
Sampi (uppercase Ϡ, lowercase ϡ) is an obsolete letter of the Greek alphabet and has a numeric value of 900 when used as a mathematical character. It may have been derived from the older letter san.
Mathematics (colloquially, maths or math) is the body of knowledge centered on such concepts as quantity, structure, space, and change, and also the academic discipline that studies them. Benjamin Peirce called it "the science that draws necessary conclusions".