
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。
Mathematics Stack Exchange
Q&A for people studying math at any level and professionals in related fields
正常人可以注射司美格鲁肽减肥吗?? - 知乎
PS:利拉鲁肽价格便宜,但是每天注射一次会觉得烦,我选择过单次注射1.8冲击,三天打一次,但是一旦变瘦皮下脂肪薄了,注射时疼痛感比胖的时候明显。
linear algebra - How to tell if a set of vectors spans a space ...
Generically you don't know without examing the presumed "basis" vectors. You do know that three vectors are sufficient (x,y,z) to span 3-space; any fourth vector must be a linear …
FanFanFan - 知乎
6 days ago · FanFanFan是知乎的用户,拥有丰富的回答经验和高赞记录,分享知识与见解。
Understanding why Minkowski’s inequality doesn't hold true for …
Understanding why Minkowski’s inequality doesn't hold true for $0 < p < 1$? Ask Question Asked 12 years, 6 months ago Modified 12 years, 6 months ago
我的电脑为何没有这个文件夹? C:\Users\你的用户 …
我的OS是 W7 1. 默认是隐藏的,所以先设置“文件夹和搜索选项”为 隐藏文件可见 2.然后再依次找,就应该能找到了
proof writing - Limit of $ (1+ x/n)^n$ when $n$ tends to infinity ...
Jul 30, 2014 · Does anyone know the exact proof of this limit result? $$\lim_ {n\to\infty} \left (1+\frac {x} {n}\right)^n = e^x$$
Paypal所谓的支持银联借记卡,实际只能绑定,支付时还是会出问 …
Paypal所谓的支持银联借记卡,实际只能绑定,支付时还是会出问题导致付款失败? 本人尝试在paypal使用工商银行和中国银行单币银联借记卡,绑定认真过程都已成功,但支付时会显示发 …
How to simplify $a^n - b^n$? - Mathematics Stack Exchange
I'd say it is already the absolute simplest form I can think of. Just as $ (a+b)^n$ is much simpler than what you get after using the binomial theorem.