A(1,2),B(3,0),C(2,4)
D : mid-point of AB
AE= (1/3)AC
DE=?
solution :
D : mid-point of AB
A(1,2),B(3,0), =>D(2,1)
AE= (1/3)AC
OE -OA = (1/3)(OC -OA)
OE -(1,2) = (1/3) [ (2,4) -(1,2) ]
= ( 1/3 , 2/3)
OE = ( 4/3, 8/3)
DE =OE -OD = ( 4/3, 8/3) - (2,1) = ( -2/3, 5/3)