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
G.729 G.729a and G.729b use the same rtpmap description as G.729. G.729a and G.729b are indicated using annexb=no or annexb=yes, respectively. G.729 Annex B (G.729b) is the default in absence of parameter "annexb" in the Session Description Protocol. G.729 G.729 is a royalty-free narrow-band vocoder-based audio data compression algorithm using a frame length of 10 milliseconds. It is officially described as "Coding of speech at 8 kbit/s using code-excited linear prediction" speech coding (CS-ACELP). The wide-band extension of G.729 is called G.729.1, which equals G.729 Annex J. Because of its low bandwidth requirements, G.729 is mostly used in voice over Internet