A.-4/3
B.-2/3
C.-1/2
D.-3/2
上面的P1P2,P2P都係向量,因為唔識打向量個符號,所以冇SHOW到出嚟~
更新1:
唔洗圖, 同埋個答案唔係c
唔洗圖, 同埋個答案唔係c
收錄日期: 2021-04-25 16:54:12
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071227000051KK03856