为什么 1 不能被认为是质数？ - 知乎 m = p 1 a 1 p 2 a 2 p 3 a 3 p n a n 什么意思呢？ 它表示这样一个结论：对于任意的一个整数，你都能把它因数分解，而且结果是唯一的。 举个例子：1001只能被分解成7×11×13，而且你再也找不到除 (7,11,13)外的一组质数，使它们的乘积是1001。 那么这个定理有什么用呢？
Why is $1 i$ equal to $-i$? - Mathematics Stack Exchange 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 than saying $1-1$ for example The complex numbers are a field This means that every non-$0$ element has a multiplicative inverse, and that inverse is unique While $1 i = i^ {-1}$ is true (pretty much by definition
Why is $1$ not a prime number? - Mathematics Stack Exchange 50 actually 1 was considered a prime number until the beginning of 20th century Unique factorization was a driving force beneath its changing of status, since it's formulation is quickier if 1 is not considered a prime; but I think that group theory was the other force
abstract algebra - Prove that 1+1=2 - Mathematics Stack Exchange 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 of some way to
If $A A^{-1} = I$, does that automatically imply $A^{-1} A = I$? A -1 A means that first we apply A transformation then we apply A -1 transformation When we apply A transformation we reach some plane having some different basis vectors but after apply A -1 we again reach to the plane have basis i ^ (0,1) and j ^ (1,0)