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cosine

trigonometric function; ratio between the lengths of the adjacent side and the hypotenuse in a right triangle
Thing Trigonometric Function Q1256164
cosine
Geek3 · Public Domain · Wikimedia

Facts

13 properties
Instance of
trigonometric function, even function, entire function[2][3]
Part of
sine and cosine[4]
Codomain
set of real numbers[9]
Defining formula
\cos\,x = \frac{\mathrm{e}^{\mathrm{i} x} + \mathrm{e}^{-\mathrm{i} x}}{2}, \cos\,x = \sin(x + \pi/2), \cos\,\theta = \frac{\text{AC}}{\text{AB}}
Definition domain
set of real numbers[8]
Described by source
ISO 80000-2:2019 Quantities and units — Part 2: Mathematics, Meyers Konversations-Lexikon, 4th edition (1885–1890), mathisfun.com[5][6][7]
Image of function
closed interval from −1 to 1[12]
In defining formula
\cos\,x, \sin\,x, \theta, \text{AC}, \text{AB}
Maintained by WikiProject
WikiProject Mathematics[13]
Mathematical inverse
arccosine, secant[14][15]
Partial function domain
set of real numbers[10]
Power series expansion
\cos(x) = \sum_{n=0}^\infty \frac{(-1)^n}{(2n)!}x^{2n} = 1 - \frac{x^2}{2!} + \frac{x^4}{4!} - \frac{x^6}{6!} + \cdots
TeX string
\cos[11]
🏷️ Also known as
en cos en cos function en cosine en cosine function ar تجب ar جتا ar جيب التمام ar جيب تمام cs cos cs cosinus cs kosinus da cossinus da cos de cos de Cosinus de Kosinusfunktion el συνημίτονο es coseno fa کسینوس fi kosinifunktio
🔖 Identifiers · 23
Australian Educational Vocabulary ID
scot/1183
De Agostini ID
coséno
Described at URL
www.mathwords.com
Digital Library of Mathematical Functions ID
4.14.E2
Encyclopedia of Mathematics article ID
Cosine
Encyclopædia Britannica Online ID
topic/cosine
Google Knowledge Graph ID
/g/120mc05f
Great Norwegian Encyclopedia ID
cosinus_-_matematikk
Interlingual Index ID
i109360
JSTOR topic ID (archived)
cosine-function
Lex ID
cosinus
Lexikon der Mathematik entry ID
1625
Show all 23 identifiers +11
MathWorld ID
Cosine
Metamath statement ID
df-cos
NLab ID
cosine
OpenMath ID
transc1#cos
ProofWiki ID
Definition:Cosine
Quora topic ID
Cosine-math-function
ScienceDirect topic ID
mathematics/cosine, mathematics/cosine-function, engineering/cosine-function, computer-science/cosine-function
Treccani ID
coseno
Treccani Vocabulary ID
coseno
Treccani's Enciclopedia della Matematica ID
coseno
Vikidia article ID
fr:Cosinus

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🔗 Connections
Instance of 3
trigonometric function, entire function, even function
Codomain 1
set of real numbers
Definition domain 1
set of real numbers
Maintained by WikiProject 1
WikiProject Mathematics
Mathematical inverse 1
arccosine
Opposite of 1
secant
Part of 1
sine and cosine
Partial function domain 1
set of real numbers
← Invariant under 1
Dottie number
← Main subject 1
sine and cosine
← Mathematical inverse 1
arccosine
← Opposite of 1
secant
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Summary

cosine is a trigonometric function[1].

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [2] ↑ . wikidata.org.
  2. [3] ↑ . wikidata.org.
  3. [4] ↑ . wikidata.org.
  4. [5] ↑ . wikidata.org.
  5. [6] ↑ . wikidata.org.
  6. [7] ↑ . wikidata.org.
  7. [8] ↑ . wikidata.org.
  8. [9] ↑ . wikidata.org.
  9. [10] ↑ . wikidata.org.
  10. [11] ↑ . wikidata.org.
  11. [12] ↑ . wikidata.org.
  12. [13] ↑ . wikidata.org.
  13. [14] ↑ . wikidata.org.
  14. [15] ↑ . wikidata.org.

Class ancestry

  1. [1] ↑ . Wikidata. wikidata.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). cosine. Retrieved November 12, 2026, from https://4ort.xyz/entity/cosine
MLA “cosine.” 4ort.xyz Knowledge Graph, 4ort.xyz, 12 Nov. 2026, https://4ort.xyz/entity/cosine.
BibTeX @misc{4ortxyz_cosine_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{cosine}}, year = {2026}, url = {https://4ort.xyz/entity/cosine}, note = {Accessed: 2026-11-12}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): cosine — https://4ort.xyz/entity/cosine (retrieved 2026-11-12)

Canonical URL: https://4ort.xyz/entity/cosine · Last refreshed:

Edit History

Rolling log of changes to this entity's Wikidata record. Values shown reflect the current state of each edited property — follow the history link to see the precise diff for any edit.

  1. 22w ago · Infovarius · 2026-06-10 view diff on Wikidata ↗
    In defining formula → \cos\,x, \sin\,x, \theta +2
    Defining formula → \cos\,x = \frac{\mathrm{e}^{\mathrm{i} x} + \mathrm{e}^{-\ma, \cos\,x = \sin(x + \pi/2), \cos\,\theta = \frac{\text{AC}}{\text{AB}}
    "Changed claim: Defining formula: \cos\,\theta = \frac{\text{AC}}{\text{AB}}"
  2. 22w ago · AddyLockPool · 2026-06-09 view diff on Wikidata ↗
    In defining formula → \cos\,x, \sin\,x, \theta +2
    "Created claim: In defining formula: \text{hypotenuse}"
  3. 22w ago · AddyLockPool · 2026-06-09 view diff on Wikidata ↗
    In defining formula → \cos\,x, \sin\,x, \theta +2
    Defining formula → \cos\,x = \frac{\mathrm{e}^{\mathrm{i} x} + \mathrm{e}^{-\ma, \cos\,x = \sin(x + \pi/2), \cos\,\theta = \frac{\text{AC}}{\text{AB}}
    Described at URL → https://www.mathwords.com/c/cosine.htm
    Described by source → ISO 80000-2:2019 Quantities and units — Part 2: Mathematics, Meyers Konversations-Lexikon, 4th edition (1885–1890), mathisfun.com
    "Created claim: Defining formula: \cos \theta = \frac{\text{adjacent}}{\text{hypotenuse}}"
  4. 22w ago · AddyLockPool · 2026-06-09 view diff on Wikidata ↗
    In defining formula → \cos\,x, \sin\,x, \theta +2
    Defining formula → \cos\,x = \frac{\mathrm{e}^{\mathrm{i} x} + \mathrm{e}^{-\ma, \cos\,x = \sin(x + \pi/2), \cos\,\theta = \frac{\text{AC}}{\text{AB}}
    "Changed claim: Defining formula: \cos\,x = \frac{\mathrm{e}^{\mathrm{i} x} + \mathrm{e}^{-\mathrm{i} x}}{2}"
Live feed via Wikidata EventStreams. New edits appear within minutes of being made on Wikidata.