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  1. Why is $1/i$ equal to $-i$? - Mathematics Stack Exchange

    May 11, 2015 · Why is 1/i 1 / i equal to −i i? Ask Question Asked 10 years, 8 months ago Modified 1 year ago Viewed 116k times

  2. If $A A^{-1} = I$, does that automatically imply $A^{-1} A = I$?

    Mar 30, 2020 · 1 Short Answer Yes AA -1 = A -1 A = I when the Det (A) ≠ ≠ 0 and A is a square matrix. Long Answer A matrix is basically a linear transformation applied to some space. For the sake of …

  3. 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 …

  4. What is the value of $1^i$? - Mathematics Stack Exchange

    Aug 30, 2010 · The formal moral of that example is that the value of 1i 1 i depends on the branch of the complex logarithm that you use to compute the power. You may already know that 1 =e0+2kiπ 1 = e …

  5. 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?

  6. 怎样评价2026年1月6日晚,牢A与瓜熟蒂落拉关于美国长生种&短命种 …

    Jan 6, 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。

  7. 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 you think …

  8. 知乎 - 知乎

    知乎是一个中文互联网高质量问答社区和创作者聚集的原创内容平台,提供知识共享、互动交流和个人成长机会。

  9. Formal proof for $(-1) \\times (-1) = 1$ - Mathematics Stack Exchange

    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?

  10. 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。