Given that ACB is a straight line such that vectorAB=3i+4j
and vector|AC|=2.
(a)find vectorAC in terms of i and j.
(b)If vectorOB = 5i+3j,find vectorOC in terms of i and j.
thanks .. f.5的
(A.MATHS)VECTOR問題X1
2009-09-17 1:34 am
回答 (1)
2009-09-17 2:10 am
✔ 最佳答案
As ACB is a straight line,vector AC lies on the same direction as vector AB.
Unit vector AB = (3i + 4j) / sqrt(32 + 42) = 3/5 i + 4/5 j
So, vector AC
= │AC│ X unit vector AB
= 2(3/5 i + 4/5 j)
= 6/5 i + 8/5 j
b. vector OB = vector OA + vector AB
vector OA = vector OB - vector AB
vector OA = (5i + 3j) - (3i + 4j) = 2i - j
vector OC = vector OA + vector AC
= (2i - j) + (6/5 i + 8/5 j)
= 16/5 i + 3/5 j
參考: Physics king
收錄日期: 2021-04-19 15:22:12
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090916000051KK00874