浙大男生强奸案：https://zh.wikipedia.org/wiki/2019%E5%B9%B4%E6%B5%99%E6%B1%9F%E5%A4%A7%E5%AD%B8%E5%BC%B7%E5%A7%A6%E6%A1%88

搞笑翻译又一例：University of Maryland, College Park成了“马里兰大学帕克分校”。据说“百度”是这么翻译的。这个错误由来已久，至少在97年就有人这么翻译。当时有一本《美国地图册》翻译成“科利奇帕克分校”，至少用了音译，不能算错。Google则翻译成“大学公园”，虽然College翻译成“学院”更合适一些，不过至少知道那是个地方，还不算太离谱。“帕克分校”实在是谬之千里。这个翻译还堂而皇之的出现在机械工业出版社出版的书上（见附图），可见所有相关人员，从翻译到编辑、校对，没有一个人去了解一下究竟是怎么回事。

A problem about the irreducibility of a polynomial (Cyclotomic polynomial). This is traditionally proved by using Eisenstein's criterion. Here we use the technique of "reduction modulo p".
#mathematics, #algebra, #polynomials, #factorization, #irreducibility

An #inequality proved by using the Cauchy-Schwarz inequality. #mathematics #algebra

A problem in #geometry solved by using #algebra, in particular #complex numbers and cyclotomic polynomial

Generalize the problem a little bit, and proved it without Galois.
#mathematics #algebra #trigonometry

This is a problem of rationality of a trigonometric sum. It was solved first using Galois theory, then I found a more elementary proof using only complex numbers. #mathematics #algebra #trigonometry #galoistheory

A problem in geometry solved by using algebra.
#mathematics #geometry #algebra #complexnumbers

Question: Joining the vertices of a triangle to the trisecting points on the opposite sides by segments, what is the area of the region enclosed by these segments in the middle of the triangle in terms of the area of the original triangle?
This is a special case of Marion's theorem. #math #geometry.

#mathematics #analysis #calculus #integration

Choose n points on a circle and connect all of them so that any three chords are not concurrent. Let f(n) be the number of regions inside the circle. What is f(n)?
#mathematics #combinatorics #algebra #geometry

#mathematics #algebra #mathtournement

#Generatingfunction #mathematics #algebra