Exercise 18

If \(\mathbf{a} = \langle 1, 0, 1 \rangle, \mathbf{b} = \langle 2, 1, -1 \rangle\), and \(\mathbf{c} = \langle 0, 1, 3 \rangle\), show that \(\mathbf{a} \times (\mathbf{b} \times \mathbf{c}) \ne (\mathbf{a} \times \mathbf{b}) \times \mathbf{c}\).