Habash al-Hasib
Habash al-Hasib | |
|---|---|
حبش الحاسب | |
| Born | Ahmad ibn ‘Abdallah al-Marwazi |
| Died | Between 864–874 (aged 100) Possibly in Abbasid Samarra, Abbasid Caliphate |
| Known for | tangent and cotangent, Kepler's equation |
| Children | Abu Ja'far ibn Habash |
| Scientific career | |
| Fields | Astronomy |
Ahmad ibn 'Abdallah al-Marwazi, known as Habash al-Hasib (Persian: حبش الحاسب, lit. 'Abyssinian calculator', died c. 869) was a Persian astronomer, geographer, and mathematician from Merv in Khorasan, who discovered the trigonometric ratios tangent, and cotangent. Al-Biruni who cited Habash in his work, expanded his astronomical tables.
Habash al-Hasib flourished in Baghdad, and died a centenarian some time between 864 and 874 possibly in Abbasid Samarra. The title "Habash" (Abbyssian) may refer to dark skin color. He worked under two Abbasid caliphs, al-Ma'mun and al-Mu'tasim.
Habash al-Hasib developed a trigonometric algorithm to solve problems related to parallax, which was later rediscovered by Johannes Kepler in 1609 and it is now known as Kepler's equation.
Habash is the father of the astronomer Abu Ja'far ibn Habash.