What is the origin of trigonometry As in a person time period or area?
Trigonometry was probably developed for use in sailing as a
navigation method used with astronomy.[2] The origins of
trigonometry can be traced to the civilizations of ancient Egypt,
Mesopotamia and the Indus Valley (India), more than 4000 years
ago.[citation needed] The common practice of measuring angles in
degrees, minutes and seconds comes from the Babylonian's base sixty
system of numeration. The first recorded use of trigonometry came
from the Hellenistic mathematician Hipparchus[1] circa 150 BC, who
compiled a trigonometric table using the sine for solving
triangles. Ptolemy further developed trigonometric calculations
circa 100 AD. The ancient Sinhalese in Sri Lanka, when constructing
reservoirs in the Anuradhapura kingdom, used trigonometry to
calculate the gradient of the water flow. Archeological research
also provides evidence of trigonometry used in other unique
hydrological structures dating back to 4 BC.[citation needed] The
Indian mathematician Aryabhata in 499, gave tables of half chords
which are now known as sine tables, along with cosine tables. He
used zya for sine, kotizya for cosine, and otkram zya for inverse
sine, and also introduced the versine. Another Indian
mathematician, Brahmagupta in 628, used an interpolation formula to
compute values of sines, up to the second order of the
Newton-Stirling interpolation formula. In the 10th century, the
Persian mathematician and astronomer Abul Wáfa introduced the
tangent function and improved methods of calculating trigonometry
tables. He established the angle addition identities, e.g. sin (a +
b), and discovered the sine formula for spherical geometry: : Also
in the late 10th and early 11th centuries, the Egyptian astronomer
Ibn Yunus performed many careful trigonometric calculations and
demonstrated the formula : Persian mathematician Omar Khayyám
(1048-1131) combined trigonometry and approximation theory to
provide methods of solving algebraic equations by geometrical
means. Khayyam solved the cubic equation x3 + 200x = 20x2 + 2000
and found a positive root of this cubic by considering the
intersection of a rectangular hyperbola and a circle. An
approximate numerical solution was then found by interpolation in
trigonometric tables. Detailed methods for constructing a table of
sines for any angle were given by the Indian mathematician Bhaskara
in 1150, along with some sine and cosine formulae. Bhaskara also
developed spherical trigonometry. The 13th century Persian
mathematician Nasir al-Din Tusi, along with Bhaskara, was probably
the first to treat trigonometry as a distinct mathematical
discipline. Nasir al-Din Tusi in his Treatise on the Quadrilateral
was the first to list the six distinct cases of a right angled
triangle in spherical trigonometry. In the 14th century, Persian
mathematician al-Kashi and Timurid mathematician Ulugh Beg
(grandson of Timur) produced tables of trigonometric functions as
part of their studies of astronomy. The mathematician Bartholemaeus
Pitiscus published an influential work on trigonometry in 1595
which may have coined the word "trigonometry" itself. Hope that
helps. :)
