Editing Delta (letter) (section)

==Lowercase==
[[File:NAMA Alphabet grec.jpg|thumb|right|The [[alphabet]] on a [[black figure]] vessel, with a D-shaped delta.]]

The lowercase letter δ (or 𝛿) can be used to denote:
* A change in the value of a variable in [[calculus]].
* A [[functional derivative]] in [[functional calculus]].
* The [[(ε, δ)-definition of limit]]s, in mathematics and more specifically in [[calculus]].<ref>{{Cite web |last=Weisstein |first=Eric W. |title=Epsilon-Delta Proof |url=https://mathworld.wolfram.com/Epsilon-DeltaProof.html |access-date=2025-01-31 |website=mathworld.wolfram.com |language=en}}</ref>
* The [[Kronecker delta]] in mathematics.<ref>{{Cite web |last=Weisstein |first=Eric W. |title=Kronecker Delta |url=https://mathworld.wolfram.com/KroneckerDelta.html |access-date=2025-01-23 |website=mathworld.wolfram.com |language=en}}</ref>
* The [[Finite difference|central difference]] for a function.<ref>{{Cite web |last=Weisstein |first=Eric W. |title=Central Difference |url=https://mathworld.wolfram.com/CentralDifference.html |access-date=2025-01-31 |website=mathworld.wolfram.com |language=en}}</ref>
* The degree of a [[vertex (graph theory)|vertex]] in [[graph theory]].
* The [[Dirac delta function]] in mathematics.<ref>{{Cite web |last=Weisstein |first=Eric W. |title=Delta Function |url=https://mathworld.wolfram.com/DeltaFunction.html |access-date=2025-01-23 |website=mathworld.wolfram.com |language=en}}</ref>
* The transition function in [[Finite-state machine|automata]].
* [[Deflection (engineering)|Deflection]] in engineering mechanics.
* The [[Compound interest|force of interest]] in actuarial science.
* The [[chemical shift]] of [[nuclear magnetic resonance]] in chemistry.
* The relative [[electronegativity]] of different atoms in a molecule, δ<sup>−</sup> being more electronegative than δ<sup>+</sup>.
* Text requiring deletion in [[proofreading]]; the usage is said to date back to classical times.
* In some of the manuscripts written by Dr. [[John Dee (mathematician)|John Dee]], the character of delta is used to represent Dee.<ref>{{Cite web |title=Greek Alphabet |url=https://www.ancient-symbols.com/greek-alphabet |access-date=2025-01-31 |website=Ancient Symbols |language=en-us |quote=Dr. John Dee, a mathematician, used the lowercase Delta symbol to represent himself in manuscripts.}}</ref>
* A subunit of the F1 sector of the [[F-ATPase]].
* The [[declination]] of an object in the [[equatorial coordinate system]] of [[astronomy]].<ref>{{Cite web |title=Greek Alphabet |url=https://www.ancient-symbols.com/greek-alphabet |access-date=2025-01-31 |website=Ancient Symbols |language=en-us |quote=In astronomy, the symbol is used to represent the declination of an object.}}</ref>
* The dividend yield in the [[Black–Scholes]] option pricing formula.
* Ratios of [[environmental isotopes]], such as [[Oxygen-18|<sup>18</sup>O]]/[[Oxygen-16|<sup>16</sup>O]] and [[Deuterium|D]]/[[Hydrogen-1|<sup>1</sup>H]] from water are displayed using [[Isotope geochemistry|delta notation]]&nbsp;– [[δ18O|δ<sup>18</sup>O]] and [[δD]], respectively.
* The rate of depreciation of the aggregate capital stock of an economy in an [[exogenous growth model]] in [[macroeconomics]].<ref>{{cite web|url=http://econ.duke.edu/people?subpage=unit&Gurl=/aas/Economics&cname=Masters+Students|title=Faculty - Economics Department|website=econ.duke.edu|access-date=26 October 2017}}</ref>
* In a system that exhibits [[electrical reactance]], the angle between [[voltage]] and [[Electric current|current]].
* [[Partial charge]] in chemistry.<ref>{{Citation |title=Declination |encyclopedia=The Encyclopedia of Astronomy and Astrophysics |date=2001 |url=https://doi.org/10.1888/0333750888/4541 |access-date=2025-01-31 |publisher=IOP Publishing Ltd |doi=10.1888/0333750888/4541 |isbn=0-333-75088-8}}</ref>
* The maximum [[birefringence]] of a crystal in [[optical mineralogy]].<ref>{{Cite book|title=Mineralogia Óptica|last=MACHADO, Fábio Braz|first=NARDY, Antônio José Ranalli|publisher=Oficina de Textos|year=2018|isbn=9788579752452|location=São Paulo|pages=85}}</ref>
*  An [[Old Irish]] voiced dental or alveolar [[fricative]] of uncertain articulation, the ancestor of the sound represented by [[irish_language|Modern Irish]] ''dh''.
*  [[Silver ratio]]<ref>{{Cite web |last=Weisstein |first=Eric W. |title=Silver Ratio |url=https://mathworld.wolfram.com/SilverRatio.html |access-date=2025-01-31 |website=mathworld.wolfram.com |language=en}}</ref>