Pi (letter)

\nPi (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 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). The upper-case letter Π is used as a symbol for:\n* The product operator in mathematics (similar to a series).\n* 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:\n* The mathematical constant &pi ≈ 3.14159, the ratio of a circle's circumference to its diameter.\n* The prime counting function in mathematics.\n* The pi mesons in particle physics.\n* Profit in microeconomics.\n* Inflation rate in macroeconomics. \n\n\n\n\n\n