Phi (letter)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Phi uc lc.svg
Greek alphabet
Αα Alpha Νν Nu
Ββ Beta Ξξ Xi
Γγ Gamma Οο Omicron
Δδ Delta Ππ Pi
Εε Epsilon Ρρ Rho
Ζζ Zeta Σσς Sigma
Ηη Eta Ττ Tau
Θθ Theta Υυ Upsilon
Ιι Iota Φφ Phi
Κκ Kappa Χχ Chi
Λλ Lambda Ψψ Psi
Μμ Mu Ωω Omega
Other letters
Ϝϝ Digamma Ⱶⱶ Heta
Ϻϻ San Ϙϙ Koppa
Ϡϡ Sampi Ϛϛ Stigma
Ϸϸ Sho

Phi (uppercase/lowercase Φ φ), is the letter of the Greek alphabet, used to represent the "ph" sound in Ancient Greek. This sound changed to "f" some time in the 1st century AD, and in Modern Greek the letter denotes the "f" sound. In the system of Greek numerals, it has a value of 500. The Cyrillic letter Ф came from Phi. In English, φ is pronounced like "f" but transliterated (re-written) as "ph" in words which originate in Ancient Greek. In those words which originate in Modern Greek, such as feta cheese, φ is translitterated as "f". The letter Phi is used in the golden Ratios and Phi represents the number approximately: 1.618033988749...