Why is $1/i$ equal to $-i$? - Mathematics Stack Exchange
2015年5月11日 · While 1/i = i−1 1 / i = i 1 is true (pretty much by definition), if we have a value c c such that c∗i = 1 c ∗ i = 1 then c= i−1 c = i 1. This is because we know that inverses in the complex numbers …
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Formal proof for $ (-1) \times (-1) = 1$ - Mathematics Stack Exchange
2020年6月13日 · 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?
If $A A^{-1} = I$, does that automatically imply $A^{-1} A = I$?
2020年3月30日 · 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 …
What is the value of $1^i$? - Mathematics Stack Exchange
2010年8月30日 · 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 …
Word,插入多级列表,但是改了1.1,第二章的2.1也变成1.1,随着改 …
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】——【定义新多级列表】,找到相应 …
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 …
abstract algebra - Prove that 1+1=2 - Mathematics Stack Exchange
2013年1月15日 · 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 …
What does $QAQ^ {-1}$ actually mean? - Mathematics Stack Exchange
2020年4月28日 · I'm self-learning Linear Algebra and have been trying to take a geometric approach to understand what matrices mean visually. I've noticed this matrix product pop up repeatedly and can't …
1/8, 1/4, 1/2, 3/4,7/8英寸分别是多少厘米? - 知乎
把1英寸分成8等分: 1/8 1/4 3/8 1/2 5/8 3/4 7/8 英寸。 This is an arithmetic sequence since there is a common difference between each term. In this case, adding 18 to the previous term in the sequence …