Look up Ξ, ξ in Wiktionary, the free dictionary.

Greek alphabet
Α α Alpha	Ν ν Nu
Β β Beta	Ξ ξ Xi
Γ γ Gamma	Ο ο Omicron
Δ δ Delta	Π π Pi
Ε ε Epsilon	Ρ ρ Rho
Ζ ζ Zeta	Σ σ ς Sigma
Η η Eta	Τ τ Tau
Θ θ Theta	Υ υ Upsilon
Ι ι Iota	Φ φ Phi
Κ κ Kappa	Χ χ Chi
Λ λ Lambda	Ψ ψ Psi
Μ μ Mu	Ω ω Omega
Obsolete letters
Ϝ ϝ Digamma	San
Ϙ ϙ Qoppa	Ϡ ϡ Sampi
Ϛ ϛ Stigma	Ϸ ϸ Sho

Xi (upper case Ξ, lower case ξ) is the 14th letter of the Greek alphabet. It is pronounced zai by English speakers, but ksi by ancient and modern Greeks. The modern Greek pronunciation has also become fairly common among mathematicians, even speaking in English. In the system of Greek numerals, it has a value of 60. Its Latin Equivelant is X. Wikipedia does not have an article with this exact name. ... Wiktionary is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... Image File history File links Greek_alphabet_xi. ... Because of technical limitations, some web browsers may not display some special characters in this article. ... Alpha (uppercase Α, lowercase α) is the first letter of the Greek alphabet. ... For other uses, see Nu. ... Beta (upper case Î’, lower case β) is the second letter of the Greek alphabet. ... Gamma (uppercase Γ, lowercase γ) is the third letter of the Greek alphabet. ... Omicron (upper case Ο, lower case ο, literally small o) is the 15th letter of the Greek alphabet. ... Look up Δ, δ in Wiktionary, the free dictionary. ... For other uses, see Pi (disambiguation) Pi (upper case Π, lower case Ï€ or Ï–) is the sixteenth letter of the Greek alphabet. ... For the 2005 hurricane, see Hurricane Epsilon. ... Rho (upper case Ρ, lower case ρ) is the 17th letter of the Greek alphabet. ... Zeta (upper case Ζ, lower case ζ) is the sixth letter of the Greek alphabet. ... For other uses, see Sigma (disambiguation). ... For other uses, see Eta. ... Tau (upper case Τ, lower case Ï„) is the 19th letter of the Greek alphabet. ... Theta (upper case Θ, lower case θ or ) is the eighth letter of the Greek alphabet. ... Upsilon (upper case , lower case ) is the 20th letter of the Greek alphabet. ... For programming language, see Iota and Jot. ... The letter phi Phi (upper case Φ or ; lower case φ, , or ), pronounced fee in Greek and fai as in defy in English, is the 21st letter of the Greek alphabet. ... For other uses, see Kappa (disambiguation). ... Chi (upper case Χ, lower case χ) is the 22nd letter of the Greek alphabet. ... Look up Λ, λ in Wiktionary, the free dictionary. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... For other uses, see Mu. ... Note: This article contains special characters. ... Digamma (upper case , lower case ) is an archaic letter of the Greek alphabet, used primarily as a Greek numeral. ... Image File history File links Greek_alphabet_san. ... San (uppercase , lowercase ) was a letter of the Greek alphabet, appearing between Pi and Qoppa in alphabetical order, corresponding in position although not in name to the Phoenician tsade. ... Qoppa Qoppa is an obsolete letter of the Greek alphabet and has a numeric value of 90. ... Sampi (Upper case Ϡ, lower case ϡ) is an obsolete letter of the Greek alphabet and has a numeric value of 900. ... Stigma is a ligature of the Greek letters sigma and tau, sometimes used nowadays to represent the Greek numeral 6. ... Sho (uppercase , lowercase ) was a letter added to the Greek alphabet in order to write the Bactrian language. ... Because of technical limitations, some web browsers may not display some special characters in this article. ... The English language is a West Germanic language that originates in England. ... Greek numerals are a system of representing numbers using letters of the Greek alphabet. ...

The lower-case letter ξ is used as a symbol for:

A joined variant of Ξ.

• Random variables
• Extent of reaction (a topic found most often in chemical engineering kinetics)
• Eigenvectors
• A parameter in a generalized Pareto distribution

The upper-case letter Ξ is used as symbol for: Image File history File links Xi_alternate. ... A random variable is a mathematical function that maps outcomes of random experiments to numbers. ... In a chemical reaction system the stoichiometric coefficient of the i–th component is defined as or where Ni is the number of molecules of i, and ξ is the progress variable or extent of reaction (Prigogine & Defay, p. ... Chemical engineering is the branch of engineering that deals with the application of physical science, e. ... In linear algebra, the eigenvectors (from the German eigen meaning own) of a linear operator are non-zero vectors which, when operated on by the operator, result in a scalar multiple of themselves. ... The Pareto distribution, named after the Italian economist Vilfredo Pareto, is a power law probability distribution that coincides with social, scientific, geophysical, and many other types of observable phenomena. ...

• The 'cascade particles' in particle physics.
• indicating "no change of state" in Z notation.

Xi was also adopted into the early Cyrillic alphabet, as the letter ksi (Ѯ, ѯ). Ξ (Xi) is a name given to a range of particles with one up or down quark and two heavier quarks. ... The Z notation (universally pronounced zed, named after Zermelo-Fränkel set theory) is a formal specification language used for describing and modelling computing systems. ... The Early Cyrillic alphabet was a writing system developed in Bulgaria during the 10th century A.D. for the writing of Old Church Slavonic. ... Ksi (Ñ®, ѯ) is a letter of the early Cyrillic alphabet, descended from the Greek letter Xi. ...