I (disambiguation)

I is the ninth letter of the Latin alphabet.

I or i may also refer to:

Language

• I (pronoun), the first-person singular subject pronoun in English
• I (Cyrillic), a letter used in almost all ancient and modern Cyrillic alphabets
• Close front unrounded vowel (i), in the International Phonetic Alphabet
• Close central unrounded vowel (ɨ), in the International Phonetic Alphabet
• Near-close near-front unrounded vowel (ɪ), in the International Phonetic Alphabet
• I (kana), one of the Japanese kana that each represent one mora
• I, male prefix to some Balinese names

Mathematics

• 1 (number) (Roman numeral: I)
• Imaginary unit (i), for which i² = −1
  • Imaginary number
• Identity matrix (I or I_n), of indeterminate size (or of size n)
• Unit interval (I), which contains all real numbers from 0 to 1 inclusive
• i, an index variable in a matrix
• I_x(a,b), the regularized incomplete beta function (of a variable x and parameters a,b)
• î, the unit vector along the x-axis in Cartesian coordinates
• i, the index of summation, used to calculate a sum

Science

Biology

• Haplogroup I (mtDNA), a human mitochondrial DNA (mtDNA) haplogroup
• Haplogroup I (Y-DNA), a Y-chromosomal DNA (Y-DNA) haplogroup
• Olfactory nerve, 1st cranial nerve, in anatomy

Chemistry

• Iodine (symbol I), a chemical element
• Isoleucine (I), an amino acid
• Ionic strength (I), in a chemical solution

Physics and astronomy

• Electric current (I, i)
• Moment of inertia (I)
• Luminous intensity (I)
• Van 't Hoff factor (i),
• Orbital inclination (i), in astronomy
• I, in the Yerkes spectral classification scheme, the symbol for supergiants

Computing

• i, a common generic index variable often used in program loops
• <i>, an HTML element for marking italic type
• .i, the common filename extension for a file that contains the output from a preprocessor
• IBM i, a computer operating system
• i-, a prefix for Apple products e.g. iMac, iPod, iPhone
• i-, an Internet-related prefix used by Internet and electronic companies

Music

• I (band), a Norwegian heavy metal band
• I, a diatonic function in tonal music theory

Albums

• i (A.R. Kane album)
• I (Cilvaringz album)
• I (Cursed album)
• I (Die Krupps album)
• I (Ikimono-gakari album)
• I (Jaejoong EP)
• I (JonnyX and the Groadies album)
• I (Kingston Wall album)
• I (Kurt Nilsen album)
• i (The Magnetic Fields album)
• I (Meshuggah EP)
• i (Misako Odani album)
• I (Nightingale album)
• I (Sahg album)
• I (Taeyeon EP)
• I (Xerath album)
• I (soundtrack), soundtrack album for the 2015 film I, by A. R. Rahman

Songs

• "I" (Kendrick Lamar song)
• "I" (Taproot song)
• "I (Who Have Nothing)", a 1966 Ben. E. King song also recorded by Tom Jones, who used the title for one of his albums
• "I", a song on Weather Systems, an album by Andrew Bird
• "I", a song on Selected Ambient Works 85–92, an album by Aphex Twin
• "I", a song on Dehumanizer, an album by Black Sabbath
• "I", a song on Coal Chamber, an album by Coal Chamber
• "I", a song on Underground, an album by The Electric Prunes
• "I", a song on Muse, an album by Jolin Tsai
• "I", a song on Music from "The Elder", an album by Kiss
• "I", a song on Eternal, an album by Samael
• "I", a song on Winter Story, an album by Shinhwa
• "I", a song on I, an EP by Taeyeon

Media

• I (film), a 2015 Tamil language Indian film
• i, a suffix unit for video resolution (vertical Interlaced lines), as in 480i or 1080i
• i (TV network), the former name of ION Television
• I band, the range of radio frequencies from 8 GHz to 10 GHz in the electromagnetic spectrum
• I, the ITU prefix allocated to Italy in radio communication
• I, in QAM modulation schemes, the in-phase communications channel
• I, in the YIQ colorspace commonly used with the NTSC television encoding scheme, the color-difference channel which is in-phase with the subcarrier
• i (newspaper), a British newspaper
• i (Portuguese newspaper), a Portuguese newspaper
• i, the international symbol for visitor or tourist information; see ISO 7001

Characters

• Goddess I, a Mayan deity
• Hou-i, or I, a heroic archer and hunter in Chinese mythology
• I, a character in the comic book series Adventure into Fear

Vehicles

• Italy (I), in the list of international license plate codes
• Italy (aircraft registration prefix)
• Mitsubishi i, a Japanese kei car

Other uses

• I-Foundation, a Hindu and ISKCON charity in charge of state-funded Hindu faith schools in the United Kingdom
• Interest rate (i), in economics
• Investment (I), in economics

See also

• 1 (disambiguation)