Why is $1/i$ equal to $-i$? - Mathematics Stack Exchange
May 11, 2015 · 67 When I entered the value 1 i 1 i in my calculator, I received the answer as −i i whereas I was expecting the answer as i−1 i 1. Even google calculator shows the same …
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 …
Formal proof for $ (-1) \times (-1) = 1$ - Mathematics Stack …
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?
abstract algebra - Prove that 1+1=2 - Mathematics Stack Exchange
Jan 15, 2013 · Possible Duplicate: How do I convince someone that $1+1=2$ may not necessarily be true? I once read that some mathematicians provided a very length proof of $1+1=2$. Can …
Word，插入多级列表，但是改了1.1，第二章的2.1也变成1.1，随着 …
注1：【】代表软件中的功能文字 注2：同一台电脑，只需要设置一次，以后都可以直接使用 注3：如果觉得原先设置的格式不是自己想要的，可以继续点击【多级列表】——【定义新多级 …
power series - How can we know the answer to 1-1+1-1+1 ...
The series does not converge, because as you observe, the partial sums $1,0,1,0,\ldots$ oscillate and do not approach a single limit. There are various ways to assign values to some divergent …
False Proof of 1=-1 - Mathematics Stack Exchange
Aug 24, 2016 · False Proof of 1=-1 [duplicate] Ask Question Asked 9 years, 4 months ago Modified 9 years, 4 months ago
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、经验和见解，找到自己的解答」为品牌使命。
Series expansion: $\frac {1} { (1-x)^n}$ - Mathematics Stack …
Jan 24, 2016 · What is the expansion for $(1-x)^{-n}$? Could find only the expansion upto the power of $-3$. Is there some general formula?
矩阵的逆怎么算？逆矩阵公式来了 (附逆矩阵计算器)
求逆矩阵通常可以通过以下几种方法： 1. 高斯-约当消元法 这是最常用的方法，通过行变换将矩阵 A 转换为单位矩阵，同时对单位矩阵进行相同的行变换，最终单位矩阵变为 A^-1。 2. 伴随矩阵 …