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cofunction

American  
[koh-fuhngk-shuhn] / ˈkoʊˌfʌŋk ʃən /

noun

Trigonometry.

  1. the function of the complement of a given angle or arc.

    cosθ is the cofunction of sinθ.
cofunction Scientific  
/ kō′fŭngk′shən /

  1. The trigonometric function of the complement of an angle. The tangent, for example, is the cofunction of the cotangent.

Etymology

Origin of cofunction

First recorded in 1905–10; co- + function

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The cofunction identities apply to complementary angles and pairs of reciprocal functions.

From Textbooks • Feb. 13, 2015

If two angles are complementary, the cofunction identities state that the sine of one equals the cosine of the other and vice versa.

From Textbooks • Feb. 13, 2015

The procedure for secant is very similar, because the cofunction identity means that the secant graph is the same as the cosecant graph shifted half a period to the left.

From Textbooks • Feb. 13, 2015

So we may state a cofunction identity: If any two angles are complementary, the sine of one is the cosine of the other, and vice versa.

From Textbooks • Feb. 13, 2015

Explain the basis for the cofunction identities and when they apply.

From Textbooks • Feb. 13, 2015

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.