Define null vector.

Three non-zero vectors vec(a), vec(b), vec(c) are such that no two of them are collinear. If the vector (vec(a)+vec(b)) is collinear with the vector vec(c) and the vector (vec(b)+vec(c)) is collinear with vector vec(a) , then prove that (vec(a)+vec(b)+vec(c)) is a null vector.

Let veca, vecb , vecc be non -coplanar vectors and let equations veca', vecb', vecc' are reciprocal system of vector veca, vecb ,vecc then prove that veca xx veca' + vecb xx vecb' + vecc xx vecc' is a null vector.

Let vec a , vec b ,a n d vec c be non-coplanar vectors and let the equation vec a^' , vec b^' , vec c ' are reciprocal system of vector vec a , vec b , vec c , then prove that vec axx vec a^'+ vec bxx vec b^'+ vec cxx vec c ' is a null vector.

Define unit vector vec A and vec B are two vectors and theta is the angle between them. If |vecA xx vecB | = sqrt3(vecA.vecB) , Calculate the value of theta .

What is null vector ?

What is a null vector?

Define cloning vector. Give example.