(i)

(i)

Show that the vectors $3\mathbf{i} - 2\mathbf{j} + \mathbf{k}$, $\mathbf{i} - 3\mathbf{j} + 5\mathbf{k}$ and $2\mathbf{i} + \mathbf{j} - 4\mathbf{k}$ form a right triangle.