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 al-Hasib is the father of the astronomer Abu Ja'far ibn Habash.