Vector Triple Product, BAC-CAB Rule
Formulas
$$ \mathbf{A} \times (\mathbf{B} \times \mathbf{C} ) = \mathbf{B}(\mathbf{A} \cdot \mathbf{C} )-\mathbf{C}(\mathbf{A} \cdot \mathbf{B}) $$
$$ \mathbf{A} \times (\mathbf{B} \times \mathbf{C} ) = \mathbf{B}(\mathbf{A} \cdot \mathbf{C} )-\mathbf{C}(\mathbf{A} \cdot \mathbf{B}) $$