知乎 - 有问题，就会有答案
知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见 …
如何打•？ - 知乎
如何在输入法里输入这个符号？Google了很多发现都不对
Why is $1$ not a prime number? - Mathematics Stack Exchange
Why is $1$ not considered a prime number? Or, why is the definition of prime numbers given for integers greater than $1$?
How can 1+1=3 be possible? - Mathematics Stack Exchange
Feb 3, 2021 · Hi, welcome to Math SE! Can you show us the proof you're looking at? There are a lot of false proofs of this sort out …
《道德经》原文及译文（1~81章）完整版，值得收藏！
《道德经》是中国历史上最伟大的哲学名著之一，对传统哲学、科学、政治、宗教、商业、科技等众多领域产生了深刻影响和深远意 …
Why is $x^{-1} = \\frac{1}{x}$? - Mathematics Stack Exchange
@turkeyhundt I don't like appealing to "common sense" results like this because it would lead one to believe that negative binomials …
有问题，就会有答案 - 知乎
知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见 …
arithmetic - Formal proof for $(-1) \times (-1) = 1$ - Mathematics ...
Is there a formal proof for $(-1) \\times (-1) = 1$? It's a fundamental formula not only in arithmetic but also in the whole of math. Is …
1-1+1-1+1-1+1... 这个无穷数列的值是什么？如何证明？ - 知乎
知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见 …
"Normalize" values to sum 1 but keeping their weights
40 10 I need to format these numbers so that they form the sum 1, but they should keep their "weight". In this specific case: 40 would …