What are the three cube roots of -1? Not sure if this is a trick question, But I have been asked this. one of the ansers is -1, what are the other 2? P标，就是经常看到的符号℗，是英文phonogram（唱片）的简写，代表录音制作者版权所有声明。 P标只用于实体唱片，在今天的互联网流媒体音乐时代已经不太常见了。 因此赵律师特意找了几张家里的黑胶唱片给大家举例。 $ 1 ^ x =1$ is not part of the definition of complex exponentiation, although it is an immediate consequence of the definition of natural number exponentiation. A second point that can be confusing is that the function ez e z $ e ^ z $ used above is really the complex exponential function exp(z) exp (z) 三国群英传从1998年开始至今，历经7个版本，还有两部网游，在资深玩家心中，哪个版本最经典，最耐玩？说… 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。 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。 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。 While looking over my notes, my lecturer stated the following inequality; As I mentioned in my answer, an algorithm cannot have a running time less than 1 step,whereas ∀k ∀ k $\mathrm \forall k$ includes constants less than 1. o(1) o (1) 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?.