Question
If 
are any four vectors in 3 - dimensional space with the same initial point and such that 
show that terminals, A, B, C, D of these vectors are coplanar. Find the point at which AC and BD meet. Find the ratio in which P divides AC and BD.
Solution
Since, 
∴ P.V. of point dividing AC in the ratio 1 : 3 is the same as the P.V. of mid-point of BD.
∴ AC and BD intersect at P whose P.V. is 
This point P divides AC in the ratio 3:1 and BD in the ratio 1:1.
