3-2

$\displaystyle \vA\cdot \left(\vB \times \vC\right) = \vB\cdot \left(\vC \times \vA\right) =\vC\cdot \left( \vA\times \vB\right)$

(7)

$\displaystyle \vA\cdot \left(\vB \times \vC\right)$	$\displaystyle = \left(A_i \ve_i\right)\cdot \left\{ \left(B_j \ve_j \right) \ti... ...left(B_j C_k \vepsilon_{jkl}\ve_l\right) =A_iB_jC_k \vepsilon_{jkl} \delta_{il}$
	$\displaystyle = A_i B_j C_k \vepsilon_{ijk}$
	$\displaystyle = A_i B_j C_k \vepsilon_{kij} =A_iB_jC_k \vepsilon_{kil} \delta_{... ...) \times \left( A_i \ve_i\right)\right\} = \vB\cdot \left(\vC \times \vA\right)$
	$\displaystyle = A_i B_j C_k \vepsilon_{jki} =A_iB_jC_k \vepsilon_{jkl} \delta_{... ...t) \times \left( B_j \ve_j\right)\right\} =\vC\cdot \left( \vA\times \vB\right)$