The number of distinct real values of β, for which the vectors

-β²i + j + k , i - β² j + k and i + j - β² k are coplanar, is :-

1. 0
2. 1
3. 2
4. 3

Dear Rohit Rastogi,

Ans:- CORRECT ANS IS 2 

Let the vectors are a,b,c

As they are coplanar and hence [abc]=0

Solving we get an equation of β which is satisfied by real values of β , iff β²=2

Hence β=+√2 or -√2

Hence 2 values of β are possible.

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