Mathematics: From the earliest the Chinese used a positional decimal system on counting boards in order to calculate. To express 10, a single rod is placed in the second box from the right. The spoken language uses a similar system to English: e.g. four thousand two hundred seven. No symbol was used for zero. By the 1st century BC, negative numbers and decimal fractions were in use and The Nine Chapters on the Mathematical Art included methods for extracting higher order roots by Horner's method and solving linear equations and by Pythagoras' theorem. Cubic equations were solved in the Tang dynasty and solutions of equations of order higher than 3 appeared in print in 1245 AD by Ch'in Chiu-shao. Pascal's triangle for binomial coefficients was described around 1100 by Jia Xian.
What advanced mathematical methods did the Tang dynasty have?
Cubic equations

Chopin arrived in Paris in late September 1831; he would never return to Poland, thus becoming one of many expatriates of the Polish Great Emigration. In France he used the French versions of his given names, and after receiving French citizenship in 1835, he travelled on a French passport. However, Chopin remained close to his fellow Poles in exile as friends and confidants and he never felt fully comfortable speaking French. Chopin's biographer Adam Zamoyski writes that he never considered himself to be French, despite his father's French origins, and always saw himself as a Pole.
What event was Frederic a part of when he arrived in Paris during the later part of September in 1831?
the Polish Great Emigration

After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible at in the late 2020s or early 2030s. However, there have been a couple of discussions to launch Neptune missions sooner. In 2003, there was a proposal in NASA's "Vision Missions Studies" for a "Neptune Orbiter with Probes" mission that does Cassini-level science. Another, more recent proposal was for Argo, a flyby spacecraft to be launched in 2019, that would visit Jupiter, Saturn, Neptune, and a Kuiper belt object. The focus would be on Neptune and its largest moon Triton to be investigated around 2029. The proposed New Horizons 2 mission (which was later scrapped) might also have done a close flyby of the Neptunian system.
When can we expect Argo to visit Triton?
2029