cosine of an angle
21arc cosine — noun the inverse function of the cosine; the angle that has a cosine equal to a given number • Syn: ↑arccosine, ↑arccos, ↑inverse cosine • Hypernyms: ↑trigonometric function, ↑circular function * * * noun …
22Direction cosine — In analytic geometry, the direction cosines of a vector are the cosines of the angles between the vector and the three coordinate axes. Or equivalently it is the component contributions to the unit vector. If v is a vector where is a basis. Then… …
23Solar azimuth angle — The solar azimuth angle is the azimuth angle of the sun. It is most often defined as the angle between the line from the observer to the sun projected on the ground and the line from the observer due south. A positive azimuth angle generally… …
24direction cosine — Math. the cosine of the angle made by a given vector and a coordinate axis. Cf. direction angle. [1890 95] * * * …
25direction cosine — noun : one of the cosines of the three angles between a directed line in space and the positive directions of the axes of a rectangular Cartesian coordinate system usually used in plural * * * Math. the cosine of the angle made by a given vector… …
26Lambert's cosine law — the intensity of radiation on an absorbing surface varies as the cosine of the angle of incidence for parallel rays …
27Tangent half-angle formula — In various applications of trigonometry, it is useful to rewrite the trigonometric functions (such as sine and cosine) in terms of rational functions of a new variable t . These identities are known collectively as the tangent half angle formulae …
28inverse cosine — noun the inverse function of the cosine; the angle that has a cosine equal to a given number • Syn: ↑arc cosine, ↑arccosine, ↑arccos • Hypernyms: ↑trigonometric function, ↑circular function * * * noun …
29Magic angle — This article is about the magic angle as defined in the field of nuclear magnetic resonance spectroscopy. For the magic angle as defined in the field of electron energy loss spectroscopy, see magic angle (EELS). The magic angle is a precisely… …
30Small-angle approximation — is a useful simplification of the laws of trigonometry which is only approximately true for finite angles, but correct in the limit as the angle approaches zero. It involves linearization of the trigonometric functions (truncation of their Taylor …
