Question

If vector i+j+k, 2i+5j, 3i+2j-3k and i-6j-k  are the position vectors of the points A, B, C and D, find the angle between vector AB and vector CD.Deduce that vector AB and CD are collinear.

Answer 1

Therefore vector AB and CD are parallel vector so vector AB and CD are collinear and angle between them is zero.

Comments

Very nice answer.  But even diagram is best for this question.