Cube root this required the construction, now known to be impossible, of the length . A method for extracting cube roots appears in "The Nine Chapters on the Mathematical Art", a Chinese mathematical text compiled around the 2nd century BCE and commented on by Liu Hui in the 3rd century CE. The Greek mathematician Hero of Alexandria devised a method for calculating cube roots in the 1st century CE. His formula is again mentioned by Eutokios in a commentary on Archimedes. In 499 CE Aryabhata, a mathematician-astronomer from the classical age of Indian mathematics and Indian astronomy, gave a method for finding
IBM 729 was introduced for the IBM 709 and IBM 705 III computers, looked identical to the IBM 727, and used vacuum tubes. The main improvement was the use of a dual gap head permitting write verify. The IBM 729 II was introduced for the IBM 7000 series computers, introducing a new cabinet style and transistorized circuitry. Supported dual density (200, 556). High speed (112.5 in/s) single density (556). High speed (112.5 in/s) dual density (200, 556). High density (800). High speed (112.6 in/s) high density (800). Introduced September 1961. IBM 729 The IBM 729 Magnetic Tape Unit was IBM's iconic tape