Pi

Pi (upper case Π, lower case π) is the 16th letter of the Greek alphabet. In the system of Greek numerals it has a value of 80.

In Greek, the letter is pronounced /piː/ (as in pee); in English, though, it is pronounced /paɪː/ (as the word pie). In words, it is pronounced /p/. In Modern Greek, the sequence of letters μπ represents the /b/ sound, as in boy (the second letter of the Greek alphabet is now pronounced /v/ as in very).

There is another variant of lower case Pi, resembling a lower case Omega: ϖ.

The upper-case letter Π is used as a symbol for:

  • The product operator in mathematics (similar to a series).
  • In textual criticism, Codex Petropolitanus, a 9th century, uncial codex of the Gospels, now located in St. Petersburg, Russia.

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

  • The mathematical constant π ≈ 3.14159, the ratio of a circle's circumference to its diameter.
  • The prime counting function in mathematics.
  • Dimensionless parameters constructed using the Buckingham Pi theorem of dimensional analysis.
  • The elementary particle called the pi meson or pion.
  • Profit in microeconomics.
  • Inflation rate in macroeconomics.

Greek alphabet
Α α Alpha Β β Beta Γ γ Gamma
Δ δ Delta Ε ε Epsilon Ζ ζ Zeta
Η η Eta Θ θ Theta Ι ι Iota
Κ κ Kappa Λ λ Lambda Μ μ Mu
Ν ν Nu Ξ ξ Xi Ο ο Omicron
Π π Pi Ρ ρ Rho Σ σ Sigma
Τ τ Tau Υ υ Upsilon Φ φ Phi
Χ χ Chi Ψ ψ Psi Ω ω Omega

Retrieved from "http://en.wikipedia.org "
All text is available under the terms of the GNU Free Documentation License