A B C D is a straight line.
O is a point so that oin-a and osi-b.
B is the midpoint of A C.
C is the midpoint of A D.
Express, in terms of a and b, the vectors
(i) A .C
(ii) O D

A B C D is a straight line O is a point so that oina and osib B is the midpoint of A C C is the midpoint of A D Express in terms of a and b the vectors i A C ii class=