tangent

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tangent
1. in immediate physical contact; touching.
2. Geom.
a. touching at a single point, as a tangent in relation to a curve or surface.
b. in contact along a single line or element, as a plane with a cylinder.
3. tangential (def. 3).
n.
4. Geom. a line or a plane that touches a curve or a surface at a point so that it is closer to the curve in the vicinity of the point than any other line or plane drawn through the point.
5. Trig.
a. (in a right triangle) the ratio of the side opposite a given angle to the side adjacent to the angle.
b. Also called tan. (of an angle) a trigonometric function equal to the ratio of the ordinate of the end point of the arc to the abscissa of this end point, the origin being at the center of the circle on which the arc lies and the initial point of the arc being on the x-axis. Abbr.: tg, tgn
c. (originally) a straight line perpendicular to the radius of a circle at one end of an arc and extending from this point to the produced radius which cuts off the arc at its other end.
6. the upright metal blade, fastened on the inner end of a clavichord key, that rises and strikes the string when the outer end of the key is depressed.
7. off on or at a tangent, digressing suddenly from one course of action or thought and turning to another: The speaker flew off on a tangent.
[1585-90; < L tangent- (s. of tangens, prp. of tangere to touch) in phrase linea tangens touching line; see -ENT]
Syn. 1. meeting, abutting.

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▪ of a curve
in geometry, straight line (or smooth curve) that touches a given curve at one point; at that point the slope of the curve is equal to that of the tangent. A tangent line may be considered the limiting position of a secant line as the two points at which it crosses the curve approach one another. Tangent planes and other surfaces are defined analogously. (See Figure—>.)

The trigonometric law of tangents is a relationship between two sides of a plane triangle and the tangents of the sum and difference of the angles opposite those sides. In any plane triangle ABC, if a, b, and c are the sides opposite angles A, B, and C, respectively, then

The formula is especially useful in making calculations using logarithms.

In trigonometry of a right triangle, the tangent of an angle is the ratio of the side opposite the angle to the side adjacent. The value of the tangent (ratio) depends only on the size of the angle, not on the particular right triangle used to compute it.

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Universalium. 2010.

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• tangent — tangent, ente [ tɑ̃ʒɑ̃, ɑ̃t ] adj. • 1683; lat. tangens, entis, de tangere « toucher » 1 ♦ Géom. Qui n a qu un point de contact en un seul point. (1705) Plan tangent à une surface : ensemble des tangentes en un point à cette surface, formant… …   Encyclopédie Universelle

• Tangent — Tan gent, n. [L. tangens, entis, p. pr. of tangere to touch; akin to Gr. ? having seized: cf. F. tangente. Cf. {Attain}, {Contaminate}, {Contingent}, {Entire}, {Tact}, {Taste}, {Tax}, v. t.] (Geom.) A tangent line curve, or surface; specifically …   The Collaborative International Dictionary of English

• tangent — TANGÉNT, Ă, tangenţi, te, adj., s.f. 1. adj. (Despre drepte) Care atinge o curbă într un singur punct. ♦ (Despre planuri) Care conţine tangente (2) la toate curbele care trec printr un punct al unei suprafeţe, care atinge suprafaţa într un singur …   Dicționar Român

• tangent — [tan′jənt] adj. [L tangens, prp. of tangere, to touch: see TACT] 1. that touches; touching 2. Geom. touching and not intersecting a curve or curved surface at one and only one point: said of a line or plane n. [< ModL ( linea) tangens, tangent …   English World dictionary

• Tangent — Tan gent, a. [L. tangens, entis, p. pr.] Touching; touching at a single point; specifically (Geom.) meeting a curve or surface at a point and having at that point the same direction as the curve or surface; said of a straight line, curve, or… …   The Collaborative International Dictionary of English

• Tangent — Ciudad de los Estados Unidos …   Wikipedia Español

• tangent — tangent, ente (tan jan, jan t ) adj. 1°   Terme de géométrie. Qui touche une ligne ou une surface en un seul point.    Une ligne droite tangente à une courbe est la limite des positions d une sécante dont un des points d intersection avec la… …   Dictionnaire de la Langue Française d'Émile Littré

• Tangent — Tangent, OR U.S. city in Oregon Population (2000): 933 Housing Units (2000): 366 Land area (2000): 3.778661 sq. miles (9.786686 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 3.778661 sq. miles (9.786686 sq.… …   StarDict's U.S. Gazetteer Places

• Tangent, OR — U.S. city in Oregon Population (2000): 933 Housing Units (2000): 366 Land area (2000): 3.778661 sq. miles (9.786686 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 3.778661 sq. miles (9.786686 sq. km) FIPS code …   StarDict's U.S. Gazetteer Places

• tangent — ► NOUN 1) a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point. 2) Mathematics the trigonometric function that is equal to the ratio of the sides (other than the hypotenuse)… …   English terms dictionary

• tangent — index close (near), proximate, tangential Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary