cosine
A trigonometric function used in connection with right triangles; best seen as a ratio of side lengths. In basic trigonometry, it is used to determine unknown side lengths or an acute angle measurement(s). In more
advanced mathematics,
cosine is treated simply as a function without an apparent or direct reference to a triangle (
the triangle's presence becomes assumed). Examples of this may be seen in Calculus through the process of integration. Wherein, the function cosine may only be a part of a large equation.
Cosine is one component out of a three-part acronym known as:
SOHCAHTOA. The term cosine occupies the "CAH," wherein the series forms: Cosine (equals) Adjacent (over)
Hypotenuse.Cosine thus represents the ratio of the Adjacent side length to the Hypotenuse side length -- this is all in relation to an (acute) angle, theta.When dealing with an angle measurement, x ("theta"), the side "touching" the angle is referred to as the Adjacent side; the side furthest away from the angle is referred to as the Opposite side; and, in a right triangle, the
hypotenuse always remains and, simplistically, may be recognized as the diagonal side.In mathematical procedures, cosine is abbreviated as "cos" for convenience.Note: UrbanDictionary entries do not support Entity, Hex or Decimal browser rendering. This definition replaces the Greek small letter, "theta", with an "x."However, in reality, it appears as an "o" or a "zero" with a line going horizontally through the center.