enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. History of trigonometry - Wikipedia

    en.wikipedia.org/wiki/History_of_trigonometry

    For the second one, the text states: "We multiply the sine of each of the two arcs by the cosine of the other minutes. If we want the sine of the sum, we add the products, if we want the sine of the difference, we take their difference". [45] He also discovered the law of sines for spherical trigonometry: [41]

  3. Sine and cosine - Wikipedia

    en.wikipedia.org/wiki/Sine_and_cosine

    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 is the ratio of the length of the adjacent leg to that ...

  4. Albert Girard - Wikipedia

    en.wikipedia.org/wiki/Albert_Girard

    He was the first to use the abbreviations 'sin', 'cos' and 'tan' for the trigonometric functions in a treatise. [1] Girard was the first to state, in 1625, that each prime of the form 1 mod 4 is the sum of two squares. [3] (See Fermat's theorem on sums of two squares.) It was said that he was quiet-natured and, unlike most mathematicians, did ...

  5. Trigonometry - Wikipedia

    en.wikipedia.org/wiki/Trigonometry

    Fig. 1a – Sine and cosine of an angle θ defined using the unit circle Indication of the sign and amount of key angles according to rotation direction Trigonometric ratios can also be represented using the unit circle , which is the circle of radius 1 centered at the origin in the plane. [ 37 ]

  6. Law of cosines - Wikipedia

    en.wikipedia.org/wiki/Law_of_cosines

    Fig. 1 – A triangle. The angles α (or A), β (or B), and γ (or C) are respectively opposite the sides a, b, and c.. In trigonometry, the law of cosines (also known as the cosine formula or cosine rule) relates the lengths of the sides of a triangle to the cosine of one of its angles.

  7. Madhava series - Wikipedia

    en.wikipedia.org/wiki/Madhava_series

    In mathematics, a Madhava series is one of the three Taylor series expansions for the sine, cosine, and arctangent functions discovered in 14th or 15th century in Kerala, India by the mathematician and astronomer Madhava of Sangamagrama (c. 1350 – c. 1425) or his followers in the Kerala school of astronomy and mathematics. [1]

  8. Timeline of geometry - Wikipedia

    en.wikipedia.org/wiki/Timeline_of_geometry

    It defines the concepts of sine and cosine, and also contains the earliest tables of sine and cosine values (in 3.75-degree intervals from 0 to 90 degrees) 7th century – Bhaskara I gives a rational approximation of the sine function

  9. Mathematical table - Wikipedia

    en.wikipedia.org/wiki/Mathematical_table

    Along with the surviving table of Ptolemy (c. 90 – c.168 CE), they were all tables of chords and not of half-chords, that is, the sine function. [1] The table produced by the Indian mathematician Āryabhaṭa (476–550 CE) is considered the first sine table ever constructed. [1] Āryabhaṭa's table remained the standard sine table of ...