Sine and cosine - Wikipedia
In mathematics, sine and cosine are trigonometric functions of an angle. The sine and cosine of an acute angle are defined in the context of a right triangle : for the specified angle, its sine is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse ), and the cosine ...

Sine, Cosine and Tangent - Math is Fun
Sine, Cosine and Tangent are the main functions used in Trigonometry and are based on a Right-Angled Triangle. Before getting stuck into the functions, it helps to give a name to each side of a right triangle: Opposite is always opposite the angle. And Adjacent is always next to the angle.

Sine, Cosine, Tangent, explained and with Examples and practice ...
This page explains the sine, cosine, tangent ratio, gives on an overview of their range of values and provides practice problems on identifying the sides that are opposite and adjacent to a given angle. The Sine, Cosine and Tangent functions express the ratios of sides of a right triangle.

Cosine Function (Cos) - Definition, Formula, Table, Graph, Questions
The cosine function (or cos function) in a triangle is the ratio of the adjacent side to that of the hypotenuse. The cosine function is one of the three main primary trigonometric functions and it is itself the complement of sine(co+sine).

Cosine - Math.net
Cosine, written as cos⁡ (θ), is one of the six fundamental trigonometric functions. There are two main ways in which trigonometric functions are typically discussed: in terms of right triangles and in terms of the unit circle.

Cosine -- from Wolfram MathWorld
The cosine function is one of the basic functions encountered in trigonometry (the others being the cosecant, cotangent, secant, sine, and tangent). Let be an angle measured counterclockwise from the x -axis along the arc of the unit circle. Then is the horizontal coordinate of the arc endpoint.

Cosine | Definition, Formulas, & Facts | Britannica
cosine, one of the six trigonometric functions, which, in a right triangle ABC, for an angle A, is cos A = length of side adjacent to angle A/ length of hypotenuse. (The other five trigonometric functions are sine [sin], tangent [tan], secant [sec], cosecant [csc], and cotangent [cot].)

Cosine Function- Definition, Graph, Formula, Table, Examples
The cosine function (cos) is one of the fundamental trigonometric functions used in mathematics, primarily in the study of angles and triangles. In simple terms, the cosine of an angle in a right-angled triangle is the ratio of the length of the adjacent side to the length of the hypotenuse.

Cosine - Graph, Meaning, Period, Examples | Cosine Function - Cuemath
In this article, we will learn the basic properties of the cosine, its graph, domain and range, derivative, integral, and its power series expansion of cosine. Cos x is a periodic function and has a period of 2π.

Cosine - math word definition - Math Open Reference
The cosine function, along with sine and tangent, is one of the three most common trigonometric functions. In any right triangle, the cosine of an angle is the length of the adjacent side (A) divided by the length of the hypotenuse (H). In a formula, it is written simply as 'cos'.