Question

已知点A(1,2)点B(3,4)求向量AB的坐标。

已知M(-2,7)，N(10,-2)，点P是线段MN上的点，且PN向=-2PM的向量，则P点的坐标为多少

Answer 1

AB=OB-OA=(2,2)
let P be (x,y)
PN = -2PM
ON-OP =-2(OM-OP)
(10-x,-2-y)=-2(-2-x,7-y)
=>
10-x = -2(-2-x) and -2-y=-2(7-y)
10-x=4+2x and -2-y=-14+2y
x=2 and y=4
P(2,4)