Kappa
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2008-07-14T02:46:05Z
Jumbuck
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robot Modifying: [[es:Κ]]
[[Image:Greek lc kappa2.png|thumb|left|75px|Variant kappa]]
{{wiktionarypar2|Κ|κ}}
{{Table_Greekletters|letter=kappa}}
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'''Kappa''' (uppercase '''Κ''', lowercase '''κ''' or '''{{Unicode|ϰ}}'''; {{lang-el|Κάππα}}) is the 10th letter of the [[Greek alphabet]], used to represent the [[voiceless velar stop]], or "k", sound in [[Ancient Greek|Ancient]] and [[Modern Greek]]. In the system of [[Greek numerals]] it has a value of 20. It was derived from the Phoenician letter [[Kaph]]. Letters that arose from kappa include the Roman [[K]] and Cyrillic [[Ka (Cyrillic)|Ka]].
Greek proper names and placenames containing kappa are often written in English with "c" due to contemporary rendering into the [[Latin alphabet]] by ancient Romans. However, modern transliteration of the Greek language invariably use the letter "k". Compare ''Κυνοσκεφαλαι'', ''Cynoscephalae'' (ancient placename); ''κυνος κεφαλαι'', ''kunos kephalai'' (phrase), meaning "[[dog]]'s [[head]]s".
[[Image:kappa-variant.PNG|frame|left|Greek word ''καί'' written with a handwritten variant of kappa, from the Byzantine period]]
In [[mathematics]], the [[kappa curve]] is named after this letter; the [[tangent]]s of this [[curve]] were first calculated by [[Isaac Barrow|Barrow]] ([[17th Century]]).
==Symbol==
In [[graph theory]], the [[Connectivity (graph theory)|connectivity]] of a [[graph (mathematics)|graph]] is given by κ.
In [[differential geometry]], the [[curvature]] of a curve is given by κ.
In [[physics]], the [[torsional constant]] of an [[oscillator]] is given by κ.
In [[chemistry]], the [[compressibility]] of a compound is given by κ.
In [[physics]], the [[dielectric constant]] of a [[capacitor]] is also given by κ.
In [[psychology]] and [[psychiatry]], kappa represents a measure of diagnostic reliability.
In [[biology]], kappa and kappa prime are important [[nucleotide]] motifs for a tertiary interaction of group II introns.
In [[biology]], kappa designates a subtype of an [[antibody]] component.
In [[pharmacology]], kappa represents a type of [[opioid receptors]].
[[Kappa statistics]] such as [[Cohen's kappa]] and [[Fleiss' kappa]] are methods for calculating interannotator agreement.
Upper-case letter Κ is used as a symbol for:
*In [[textual criticism]], the [[Byzantine text-type]] (from Κοινη, ''Koine'', the common text).
[[Category:Greek letters]]
[[als:Κ]]
[[ar:كبا (حرف إغريقي)]]
[[arc:Κ]]
[[br:Kappa (lizherenn)]]
[[bg:Капа (буква)]]
[[ca:Kappa]]
[[cy:Kappa]]
[[da:Kappa]]
[[de:Kappa]]
[[el:Κάππα]]
[[es:Κ]]
[[eo:Kapo (litero)]]
[[ext:Capa]]
[[eu:Kappa]]
[[fr:Kappa]]
[[ga:Capa]]
[[gd:Kappa]]
[[gl:Kappa]]
[[ko:Κ]]
[[hr:Kapa]]
[[is:Kappa]]
[[it:Kappa (lettera)]]
[[he:קפא]]
[[ka:კაპა (ასო)]]
[[ht:Κ]]
[[ku:Kappa]]
[[la:Cappa]]
[[lt:Kapa (raidė)]]
[[hu:Kappa]]
[[ms:Kapa]]
[[nah:Κ]]
[[nl:Kappa (letter)]]
[[ja:Κ]]
[[no:Kappa (bokstav)]]
[[nn:Kappa]]
[[nds:Kappa]]
[[pl:Kappa (litera)]]
[[pt:Κ]]
[[ru:Каппа (буква)]]
[[simple:Kappa (letter)]]
[[sk:Kapa]]
[[sl:Kapa (črka)]]
[[sh:Kapa]]
[[fi:Kappa (kirjain)]]
[[sv:Kappa (bokstav)]]
[[th:แคปปา]]
[[vi:Kappa]]
[[tr:Κ]]
[[uk:Каппа (літера)]]
[[vo:Kappa]]
[[zh:Κ]]