Abu Sahl al-Quhi
Videos
Abū Sahl Wayjan ibn Rustam al-Kūhī was a Persian mathematician, physicist and astronomer. He was from Kuh, an area in Tabaristan, Amol, and flourished in Baghdad in the 10th century. He is considered
Engraving of al-Qūhī's perfect compass to draw conic sections
Conic section
Videos
A conic section, conic or a quadratic curve is a curve obtained from a cone's surface intersecting a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse; the circl
This diagram clarifies the different angles of the cutting planes that result in the different properties of the three types of conic section.
Types of conic sections: 1: Circle 2: Ellipse 3: Parabola 4: Hyperbola
Diagram from Apollonius' Conics, in a 9th-century Arabic translation
Table of conics, Cyclopaedia, 1728