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  1. 1/1+1/2+1/3+1/4+……+1/n=?怎么个解法? - 知乎

    两边求和,我们有 ln (n+1)<1/1+1/2+1/3+1/4+……+1/n 容易的, \lim _ {n\rightarrow +\infty }\ln \left ( n+1\right) =+\infty ,所以这个和是无界的,不收敛。

  2. 为什么 1 不能被认为是质数? - 知乎

    质数就是“只能被1和它本身整除”的自然数。 然而,我们必须在此基础之上增加一条警告,宣称数字1不是质数,这简直就像马后炮一样。

  3. 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、经验和见解,找到自己的解答」为品牌使命。

  4. 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。

  5. 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?

  6. 如何评价良子12月1日最新公开的体检报告? - 知乎

    如何评价良子12月1日最新公开的体检报告? B站UP主北美运动学博士Bruce_PhD经良子本人同意,公开并解读了良子最新的体检报告 [图片] [图片] [图片] [图片]

  7. 如何评价麦当劳1+1随心配涨价到14.9元? - 知乎

    如何评价麦当劳1+1随心配涨价到14.9元? 2025年12月15日,在麦当劳点餐界面,可以看见,1+1随心配套餐中,若选择双层吉士汉堡,需要加1元,即总价14.9元;也可以选择高达吉士汉堡,不需…

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

    Aug 30, 2010 · There are infinitely many possible values for $1^i$, corresponding to different branches of the complex logarithm. The confusing point here is that the formula $1^x = 1$ is not part of the …

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

    May 11, 2015 · 11 There are multiple ways of writing out a given complex number, or a number in general. Usually we reduce things to the "simplest" terms for display -- saying $0$ is a lot cleaner …

  10. 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 …