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  1. Sine and cosine - Wikipedia

    In mathematics, sine and cosine are trigonometric functions of an angle.

  2. 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 …

  3. Cosine Function in Math - Definition, Formula, Examples

    Feb 4, 2025 · Learn about the cosine function in math. Get its definition, formula, and examples in trigonometry, geometry, and calculus.

  4. Cosine | Definition, Formulas, & Facts | Britannica

    The cosine is a fundamental trigonometric function such that the cosine of an angle of a right triangle is the ratio of its adjacent side to the hypotenuse.

  5. Cosine -- from Wolfram MathWorld

    The cosine function cosx is one of the basic functions encountered in trigonometry (the others being the cosecant, cotangent, secant, sine, and tangent). Let theta be an angle measured …

  6. cosine - Wiktionary, the free dictionary

    5 days ago · cosine (plural cosines) (trigonometry) In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. Symbol: cos

  7. The Sine and Cosine Functions - University of Nebraska–Lincoln

    The special values of sine and cosine in the first quadrant are very useful to know, since knowing them allows you to quickly evaluate the sine and cosine of common angles without needing to …

  8. Cosine Function (Cos) - GeeksforGeeks

    Jul 23, 2025 · 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 …

  9. 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 …

  10. cos (x) | cosine function - RapidTables.com

    Cosine definition In a right triangle ABC the cosine of α, cos (α) is defined as the ratio betwween the side adjacent to angle α and the side opposite to the right angle (hypotenuse):