Vertices O, A and B form a triangle. Y is the midpoint of AB.
A is the midpoint of OZ.
−−→
O
A
=
2
a
−−→
O
X
=
4
b
−−→
X
B
=
2
b
Express:
(i) the vector
−−→
X
Y
in terms of
a
and/or
b
.
(ii) the vector
−−→
Y
Z
in terms of
a
and/or
b
.
Explain if XYZ are in a straight line in the comment box giving a reason for your answer.