Editing Trigonometric functions (section)

==Etymology==
{{main|History of trigonometry#Etymology}}
The word {{Lang|la-x-medieval|sine}} derives<ref>The anglicized form is first recorded in 1593 in [[Thomas Fale]]'s ''Horologiographia, the Art of Dialling''.</ref> from [[Latin]] ''[[wikt:sinus|sinus]]'', meaning "bend; bay", and more specifically "the hanging fold of the upper part of a [[toga]]", "the bosom of a garment", which was chosen as the translation of what was interpreted as the Arabic word ''jaib'', meaning "pocket" or "fold" in the twelfth-century translations of works by [[Al-Battani]] and [[Muḥammad ibn Mūsā al-Khwārizmī|al-Khwārizmī]] into [[Medieval Latin]].<ref>Various sources credit the first use of {{Lang|la-x-medieval|sinus}} to either 
* [[Plato Tiburtinus]]'s 1116 translation of the ''Astronomy'' of [[Al-Battani]]
* [[Gerard of Cremona]]'s translation of the ''Algebra'' of [[Muḥammad ibn Mūsā al-Khwārizmī|al-Khwārizmī]]
* [[Robert of Chester]]'s 1145 translation of the tables of al-Khwārizmī
See Merlet, [https://link.springer.com/chapter/10.1007/1-4020-2204-2_16#page-1 ''A Note on the History of the Trigonometric Functions''] in Ceccarelli (ed.), ''International Symposium on History of Machines and Mechanisms'', Springer, 2004<br>See Maor (1998), chapter 3, for an earlier etymology crediting Gerard.<br>See {{cite book |last=Katx |first=Victor |date=July 2008 |title=A history of mathematics |edition=3rd |location=Boston |publisher=[[Pearson (publisher)|Pearson]] |page=210 (sidebar) |isbn= 978-0321387004 |language=en }}</ref>
The choice was based on a misreading of the Arabic written form ''j-y-b'' ({{lang|ar|[[:wikt:جيب|جيب]]}}), which itself originated as a [[transliteration]] from Sanskrit ''{{IAST|jīvā}}'', which along with its synonym ''{{IAST|jyā}}'' (the standard Sanskrit term for the sine) translates to "bowstring", being in turn adopted from [[Ancient Greek language|Ancient Greek]] {{lang|grc|[[Chord (geometry)|χορδή]]}} "string".<ref name="Plofker_2009"/>

The word ''tangent'' comes from Latin ''tangens'' meaning "touching", since the line ''touches'' the circle of unit radius, whereas ''secant'' stems from Latin ''secans''—"cutting"—since the line ''cuts'' the circle.<ref>Oxford English Dictionary</ref>

The prefix "[[co (function prefix)|co-]]" (in "cosine", "cotangent", "cosecant") is found in [[Edmund Gunter]]'s ''Canon triangulorum'' (1620), which defines the ''cosinus'' as an abbreviation of the ''sinus complementi'' (sine of the [[complementary angle]]) and proceeds to define the ''cotangens'' similarly.<ref name="Gunter_1620"/><ref name="Roegel_2010"/>