In mathematics, the gamma function is one commonly used extension of the factorial function to complex numbers. The gamma function is defined for all complex numbers except the non-positive integers. For every positive integer n,

Gamma is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop IPA: [ɡ]. In Modern Greek, this letter normally represents a voiced velar fricative IPA: [ɣ], except before either of the two front vowels, where it represents a voiced palatal fricative IPA: [ʝ]; while /g/ in foreign words is instead commonly transcribed as γκ).