If the vectors a, b and c are coplanar, then `|{:(a, b, c),(a*a, a*b,a*c),(b*a,b*b,b*c):}|` is equal to

Theorem 3: If vectors a; b and c are coplanar then det(a;b;c)=0

Suppose a, b, c are three non-coplanar vectors. Suppose Delta=|{:(a*a, a* b, a*c), (b*a, b*b, b*c), (c*a, c*b, c*c):}| If Delta=[a b c]^(r)" then " r= _______

If a, b and c are unit coplanar vectors, then [[2a-b, 2b-c, 2c-a]] is equal to