CBSE

MATHEMATICS · Single correct · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

\mathbf{u} = \hat{i} \times (\mathbf{a} \times \hat{i}) + \hat{j} \times (\mathbf{a} \times \hat{j}) + \hat{k} \times (\mathbf{a} \times \hat{k})

, then (1)

\mathbf{u} = 0

(2)

\mathbf{u} = \hat{i} + \hat{j} + \hat{k}

(3)

\mathbf{u} = 2\mathbf{a}

(4)

\mathbf{u} = \mathbf{a}