Mathematics

Problem

\mathbf{u}, \mathbf{v}

and

\mathbf{w}

are three non-coplanar vectors, then

(\mathbf{u} + \mathbf{v} - \mathbf{w}) \cdot [(\mathbf{u} - \mathbf{v}) \times (\mathbf{v} - \mathbf{w})]

equal to a. 0 b.

\mathbf{u} \cdot \mathbf{v} \times \mathbf{w}

\mathbf{u} \cdot \mathbf{w} \times \mathbf{v}

3\mathbf{u} \cdot \mathbf{v} \times \mathbf{w}