Contact us
Choose a category below so we can get back to you as quickly as possible.
用公式:a×a=0,a×b=-b×a BA×BC=1/2(2a+b-c)×1/2(a+c) =1/4(2a×c+b×a+b×c-c×a) =1/4(3a×c+b×a+b×c)
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.