题目背景: 在t教师课后, w同学提出此问题. 在现场的我由于过于弱智, 没能及时想出思路. 在回家途中准备展开时, 却无意中发现了"绝妙"的突破口. :i 题目: 求\prod_{i=1}^{n}(1+cos\frac{2i\pi}{n}) 先想再看提示哦 提示: 切比雪夫多项式 ……

chemistry 思考题 Hydrocarbon Ninetail is building a tree. She has N nodes and she will assign a value from 0 to 3 to each node. All nodes with the same value are indistinguishable. Then she will connect the N nodes with N-1 edges so that they form ……

OBCYSIO Ep.41 to 43 is hosted on XGN's blog. As I am lazy to copy, please read them here

From Hexo Useful 思考题!! Replace Hikari is a cute white dragon girl. She is helping Ninetail - a fox girl, her master - correct composition.The original composition is a string S and the corrected one is another string T. Hikari claimed that……

From Hexo String 思考题!! Boggle Constructor Ninetail is a clever fox girl. She loves to play Boggle! the rules are simple: Each player searches for words that can be constructed from the letters of sequentially adjacent cubes, where "adjace……

By HDD from Hexo 时隔多月, CB终于归来. 这次的题目虽然不难, 但解答过程可谓是一波三折: A在告诉我题目后, 我自然地尝试用复数解. 可惜由于我太过弱智, 将积的模记成了模相乘再开根, 导致与正确题解失之交臂, 并报告了A复数行不通. A随后告诉我B用复数解决, 我……

By MonkeyKing from Hexo 所谓algorithms unweekly， 就是开心的时候就写点的有关的algorithms的blog, 如果你喜欢weekly的algorithms, 请移步这里Algorithms weekly by Petr。 那么你现在看到的就是第一篇algorithms unweekly，这篇文章讲的是笔者2020年第四季……

由于笔者太弱智,这道题想了两天无任何思路.但在上完夏建国课后,突然思如泉涌,在10分钟内完成,金与大家分享一下我的歪门邪道 题面 已知x_i>0(i=1,2,...,n),x_1+x_2+...+x_n\geq x_1x_2...x_n(n\geq2),且1\leq\alpha\leq n 证明:\frac{x_1^\alpha+x_2^\alpha+...+x_n^\a……

简易琴生不等式两则,能使你在繁重的中考学习压力下锻炼思维,获得成功的快感!!! 1.x,y,z\in \mathbb{R}^+,xyz=1,证明: \frac{x^3}{(1+y)(1+z)}+\frac{y^3}{(1+x)(1+z)}+\frac{z^3}{(1+x)(1+y)}\geq\frac{3}{4} 2.\alpha>\beta>0.a_1,a_2,...a_n\in\mathbb{R}^+,证明: (……

注意:理解曲线系最重要的要点是将某方程F(x,y)=0中的多项式F(x,y)当做关于一点坐标的函数.当一点(m,n)在F(x,y)=0的图像上时,便满足F(m,n)=0 1.先从一道不能算曲线系精髓的直线系题目说起 如图AD平分∠BAC,AD上任取一点E,使得BE交边CD于F,CE交边BD于G 求证AD平分∠GAE ……