Mark (√) against the correct answer in the following:
It is given that the vectors 
and 
are coplanar. Then, the value of λ is
Given 
And 
=
are the coplanar.
If three vectors 
are coplanar, then [
[
=0
⇒2[2(1+
)]-2[-4(1+
=0
⇒4(1+
)+8(1+
)=0
⇒12(1+
)=0
⇒λ=-1
1