cosine: Quick Facts

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Facts

Also Known As	cos

Photos

Diagram of a right triangle labeled with sides a, b, and hypotenuse c, alongside formulas for the six trigonometric functions-sine, cosine, tangent, cosecant, secant, and cotangent-each defined by ratios of the triangle's sides.

Four graphs display the curves of sine, cosine, tangent, and cotangent functions, each labeled with x- and y-axes, key angles in radians, and typical wave or asymptote patterns.

Bessel functions

Trihedral angles for derivation of the laws of (left) sines and (right) cosines for spherical trigonometry.

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Topics

law of cosines secant trigonometric function tangent sine cosecant cotangent