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Period: 125 to 180
First Trigonometric Tables
The first table compiled on trigonometric values of arc and chord for a series of angle measurements was created by Hipparchus of Nicaea -
147
Claudius Ptolemy's Theorems
AD
Ptolemy expanded on Hipparchus's work and created a table of his own on chord values. He also develeoped the first evidence of several trigonometric identities in his Almagest, such as the half-angle formula, and the sum and difference formulas of sine and cosine. -
150
First Trigonometric Tables
BCE.
The first table compiled on trigonometric values of arc and chord for a series of angle measurements was created by Hipparchus of Nicaea -
499
Further Developments of Sine and Cosine Tables
Aryabhata, an Indian mathematician and astronomer, expanded on the works of the Siddhantas and created many sine and cosine tables. He published these works in the Aryabhatiya. -
500
Trionometry Moves to India
AD
Major developments are made in India in the fifth and sixth centuries by the five Siddhantas (Indian philosophies), which outlined the conventions of trigonometric ratios and how they are used in astronomical observations. -
Jan 1, 820
First Table of Tangents
AD
Muhammad ibn Mūsā al-Khwārizmī develops the first table of tangents of certain measures of angles. -
Jan 1, 830
First Table of Cotangents
AD
Habash al-Hasib al-Marwazi developes the first table of cotangent values of certain angle measurements. -
Jan 1, 875
First Tables of Cosecant and Secant
AD
Muhammad ibn Jābir al-Harrānī al-Battānī developes the first tables of the reciprocal functions secant and cosecant for certain angle measures. -
Jan 1, 990
Law of Sines is Discovered
AD
Abū al-Wafā' al-Būzjānī, a Persian mathematician is using all six trigonometric functions, and developes the Law of Sines for spherical trigonometry. -
Jan 1, 1150
Sum and Difference Identites are Discovered
AD
Bhaskara II, an Indian mathematician of the 12th century, was the first to develope the formulas
sin(a+b)=sin(a)cos(b)+cos(a)sin(b)
sin(a-b)=sin(a)cos(b)-cos(a)sin(b) -
Jan 1, 1400
Madhava Uses Inifinte Taylor Series to Expand Sine, Cosine, Tangent and Arctangent
AD
The indian mathematician uses what will become to be known as Taylor series expansions to produce the values of trigonometric functions with a new record of accuracy. He also developed expansion series for pi. -
Right Triangle Trigonometry is Invented
After trigonometry finally makes its way to Western Europe, Georg Joachim Rheticus, a student of Copernicus, is the first to define all six trigonometric functions in terms of right triangles in his work, The Opus palatinum de triangulis. -
Euler's Formula
Euler's famous identity is published.
e ^ (ix) = cos (x) + isin (x)