Abul Wafa Muhammad Ibn Muhammad Ibn Yahya Ibn Ismail al-Buzjani (940 – 997 or 998) was a mathematician and astronomer in Baghdad. He was born in Buzjan , Nishapur in Iran.
He is one of the founders of Trigonometry.
He established the relations:
- Sin(a+b) = Sin a Cos b + Cos a Sin b
- Cos2a = 1 - 2Sin2a
- Sin2a = 2 Sina Cosa
and dicovered the Sine formula for spherical geometry:
- SinA/Sina = SinB/Sinb = SinC/Sinc
His constructions were so eminently serviceable that they were widely circulated in Europe during the Renaissance. He also prepared new Trigonometric tables and developed novel ways of solving some problems of spherical triangles.
In 959 A.D. he moved to Iraq. He studied mathematics and worked principally in the field of trigonometry. He wrote a number of books, most of which no longer exist. He also studied the movements of the moon.
See also
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