If are non–zero, non-coplanar vectors, prove that the following vectors are coplanar :

and

We have been given that, , and .

We can form a relation using these three vectors. Say,





Compare the vectors , and . We get


1 = – 2y …(1)


–2 = –3x + 3y …(2)


3 = 5x – 4y …(3)


Solving equation (1) for y,


Equation (1), –2y = 1



Put in equation (2), we get





–6x – 3 = –2 × 2


–6x – 3 = –4


–6x = –4 + 3


–6x = –1



Substituting and in equation (3), we get


3 = 5x – 4y


Or 5x – 4y = 3







But


, L.H.S ≠ R.H.S


The value of x and y doesn’t satisfy equation (3).


Thus, , and are not coplanar.


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