co-sine

cosine

[koh-sahyn]
noun
1.
Trigonometry.
a.
(in a right triangle) the ratio of the side adjacent to a given angle to the hypotenuse.
b.
the sine of the complement of a given angle or arc. Abbreviation: cos
2.
Mathematics. (of a real or complex number x ) the function cos x defined by the infinite series 1 − (x 2 /2!) + (x 4 /4!) − + …, where ! denotes factorial. Abbreviation: cos Compare sine ( def 3 ), factorial ( def 1 ).

Origin:
1625–35; < Neo-Latin cosinus. See co-, sine1

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To co-sine
Collins
World English Dictionary
cosine (ˈkəʊˌsaɪn)
 
n
cos a trigonometric function that in a right-angled triangle is the ratio of the length of the adjacent side to that of the hypotenuse; the sine of the complement
 
[C17: from New Latin cosinus; see co-, sine1]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Etymonline
Word Origin & History

cosine
1630s, from co- + sine.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Science Dictionary
cosine   (kō'sīn')  Pronunciation Key 
  1. The ratio of the length of the side adjacent to an acute angle of a right triangle to the length of the hypotenuse.

  2. The abscissa of the endpoint of an arc of a unit circle centered at the origin of a Cartesian coordinate system, the arc being of length x and measured counterclockwise from the point (1, 0) if x is positive or clockwise if x is negative.

  3. A function of a number x, equal to the cosine of an angle whose measure in radians is equal to x.


The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature