What does $QAQ^{-1}$ actually mean? - Mathematics Stack …
Apr 28, 2020 · 1 $\begingroup$ When one thinks of matrix products like that, it's helpful to remember that matrices, unlike vectors, have two sets of bases: one for the domain and one …
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、经验和见解，找到自己的解答」为品牌使命。知乎凭借认真、专业 …
abstract algebra - Prove that 1+1=2 - Mathematics Stack Exchange
Jan 15, 2013 · The main reason that it takes so long to get to $1+1=2$ is that Principia Mathematica starts from almost nothing, and works its way up in very tiny, incremental steps. …
2025年618哪一款手机性价比高？全品牌、全价位手机推荐与选购 …
3 days ago · 1、华为 作为国民品牌的华为，基本上是家喻户晓的，除了华为公司知名度高、实力雄厚之外，它的手机确实很值得称赞。 华为手机不论是是高端机还是低端机，在机子的做工 …
Binomial expansion of $(1-x)^n$ - Mathematics Stack Exchange
(1+a)^n This yields exactly the ordinary expansion. Then, by substituting -x for a, we see that the solution is simply the ordinary binomial expansion with alternating signs, just as everyone else …
Mathematics Stack Exchange
Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their …
电脑有几种截图方法？电脑如何快速截图？ - 知乎
1、电脑系统截图. 不同电脑系统的截图快捷键有所不同： Windows 系统：-全屏截图：Print Screen（PrtSc）键，按下后可在画图等软件中粘贴。 - 当前窗口截图：Alt + Print …
Formula for $1^2+2^2+3^2+...+n^2$ - Mathematics Stack …
Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their …
How can 1+1=3 be possible? - Mathematics Stack Exchange
Feb 3, 2021 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for …
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?