(adsbygoogle = window.adsbygoogle || []).push({}); Let a and b be non-zero parallel vectorsand let the points A,B,C and D be given by OA=a, OB=b, OC= 3a-b,OD = -a+2b

a) express the vectors AB,AC,AD,BC,BD and CD in terms of a and b.

b) Find, in terms of a and b, vectors from the origin to the midpoints of the line segments AB and CD.

3. The attempt at a solution

a) AB = b-a

AC = (3a-b)-a = 2a-b

AD = (-a+2b)-a = -2a+2b

BC = (3a-b)-b = 3a-2b

BD = (-a+2b)-b = -a+b

(-a+2b)-(3a-b) = -4a+b

Hope it's right.

b) I don't know how to do question. I appreciate it if someone could give me some guidance and show me how to solve this question.

Thanks!

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# Homework Help: Parallel Vectors

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