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cos θ = b/c
n. Abbr. cos
1. In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse.
2. The abscissa at 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.
(of an angle) n
(Mathematics) 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. Abbreviation: cos
[C17: from New Latin cosinus; see co-, sine1]
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. Abbr.: cos
The ratio of the length of the side adjacent to an acute angle of a right triangle to the length of the hypotenuse.