-
The Egyptians used special right triangles to survey land by measuring out 3-4-5 right triangles to make right angles.
-
-
-
"The area of the square built upon the hypotenuse of a right triangle is equal to the sum of the areas of the squares upon the remaining sides." Though we name this theorem after the Greek mathematician Pythagoras who lived approximately 570−495 BC, it was known and recorded by the Babylonian mathematicians about 1000 years earlier. It was also discovered independently by other ancient civilisations in Mesopotamia, India and China.
-
debated over whether he invented it or not
-
The table of chords, created by the Greek astronomer, geometer, and geographer Ptolemy in Egypt during the 2nd century AD, is a trigonometric table in Book I, chapter 11 of Ptolemy's Almagest, a treatise on mathematical astronomy. It is essentially equivalent to a table of values of the sine function. Ptolemy expanded on Hipparchus's work and created a table of his own on chord values. He also developed the sum and difference formulas of sine and cosine
-
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.
-
Abū al-Wafā' al-Būzjānī, a Persian mathematician is using all six trigonometric functions, and developes the Law of Sines for spherical trigonometry.
-
Bhaskara II, an Indian mathmetician of the 12th century, was the first to develope the formulas:
sin(a+b)=sin(a)+(cos)(a)sin(b)
sin(a-b)=sin(a)cos(b)-cos(a)sin(b) -
Gerardo of cremona works to translate the works of ptolmey and Hipparchus from Arab into Latin
-
The indian mathematician, Madhava, 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
-
After trigonometry finally makes its way to Western Europe, Georg Joachim Rheticus, a student of Copernicus, is the first to define all six trigonomic functions in terms of right triangles in his work, The Opus palatinum de triangulis
-
Eulers famous identity is published:
e^(ix) = cos(x) + isin(x)