Contact us
Choose a category below so we can get back to you as quickly as possible.
這題可以間接驗證: 由(a-b)^2>=0得a^2+b^2>=2ab 相似的可以得到 (a-c)^2>=0 a^2+c^2>=2ac (b-c)^2>=0 b^2+c^2>=2bc 把3個不等式相加就可以得到 a^2+b^2+c^2>=ab+ac+bc
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.