Question

（英文）题Find the position vector of a point R which divides the

Answer 1

1.

若R在PQ间

R(1/3,4/3,-1)

若R在PQ外

R（-3,-2,-1）

2.

OA=(3,2,-1),OB=(2,3,4),OC=(0,5,14)

OC=λOA+（1-λ)OB

(0,5,14)=λ(3,2,-1)+(1-λ)(2,3,4)

λ=-2