(of an angle) a trigonometric function that in a right-angled triangle is the ratio of the length of the adjacent side to that of the opposite side; the reciprocal of tangent
Abbreviation: cot, cotan, ctn
Derived forms
cotangential (ˌkəʊtænˈdʒɛnʃəl)
adjective
cotangent in American English
(koʊˈtændʒənt; ˈkoʊˌtændʒənt)
noun
TrigonometryMathematics
the reciprocal of the tangent
; specif.
a.
the ratio of the adjacent side of a given acute angle in a right triangle to the opposite side
b.
an equivalent, positive or negative ratio for certain related angles (Ex.: the cotangent of 57° or 237° is .6494, of 123° or 303° is −.6494) or real numbers representing radians (Ex.: the cotangent of .9948 radians (57°) is .6494)
Word origin
ModL cotangens < co. tangens, short for complementi tangens, lit., tangent of the complement