1. If p,q,r and s are coplanar, prove that (pxq)x(rxs)=0
2. It is given that (pxq) .r =5. Find the value of (p+r). ((p+q)x(q+r))
3. If a+b+c=0, prove that axb=bxc=cxa
數學vector
2011-11-06 1:22 am
回答 (1)
2011-11-06 7:06 pm
✔ 最佳答案
http://i1090.photobucket.com/albums/i376/Nelson_Yu/int-135.jpg圖片參考：http://i1090.photobucket.com/albums/i376/Nelson_Yu/int-135.jpg
2011-11-06 22:24:54 補充：
There is a typo in question (1). p x q and r x s are co-linear
The cross product of 2 co-linear vector = 0
收錄日期: 2021-04-23 23:24:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111105000051KK00683