
Why is $1$ not a prime number? - Mathematics Stack Exchange
Jun 28, 2022 · 50 actually 1 was considered a prime number until the beginning of 20th century. Unique factorization was a driving force beneath its changing of status, since it's formulation is quickier if 1 is …
Formal proof for $ (-1) \times (-1) = 1$ - Mathematics Stack Exchange
Jun 13, 2020 · 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 there a proof for it or is it just assumed?
Series expansion: $\frac {1} { (1-x)^n}$ - Mathematics Stack Exchange
Dec 2, 2024 · What is the expansion for $(1-x)^{-n}$? Could find only the expansion upto the power of $-3$. Is there some general formula?
elementary number theory - Prove $ x^n-1= (x-1) (x^ {n-1}+x^ {n-2 ...
Aug 17, 2014 · 13 So what I am trying to prove is for any real number x and natural number n, prove xn − 1 = (x − 1)(xn−1 +xn−2 + ⋯ + x + 1) x n 1 = (x 1) (x n 1 + x n 2 + + x + 1) I think that to prove this I …
algebra precalculus - Prove $0! = 1$ from first principles ...
How can I prove from first principles that $0!$ is equal to $1$?
factorial - Why does 0! = 1? - Mathematics Stack Exchange
Possible Duplicate: Prove 0! = 1 0! = 1 from first principles Why does 0! = 1 0! = 1? All I know of factorial is that x! x! is equal to the product of all the numbers that come before it. The product of 0 and …
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 there, typically involving division by 0, I would imagine that's probably the …
calculus - Proof of $\lim_ {x\to a}f^ {g}=e^ {\lim_ {x\to a} { (f-1)g ...
Oct 27, 2016 · There is a general formula for indeterminate form 1∞ 1 ∞ which I'm looking for a proof which is also used here. (picture) Given
如何定义什么是 1? - 知乎
May 9, 2018 · 我们可以从数学上证明 1+1=2,但是如何定义 1 是什么。如果说是 0 的后继数,那又如何定义 0 呢?
如何看待2026年1月29日A股行情? - 知乎
Jan 26, 2026 · 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、经验和见解,找到自己的解答」为品牌使命。