问题描述：
（英文）题
Find the position vector of a point R which divides the line joining two points P and Q whose position vectors are i + 2j - k and -i + j - k respectively in the ratio 2:1 internally and externally
还有知道A(3,2,-1),B(2,3,4) 和 C(0,5,14) 三个点,怎么证明它们在同一条直线上?
Find the position vector of a point R which divides the line joining two points P and Q whose position vectors are i + 2j - k and -i + j - k respectively in the ratio 2:1 internally and externally
还有知道A(3,2,-1),B(2,3,4) 和 C(0,5,14) 三个点,怎么证明它们在同一条直线上?
问题解答：
我来补答展开全文阅读