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.