<Dd> c p q r s = l p i l q j l r k l s l c i j k l (\ displaystyle c_ (pqrs) = l_ (pi) l_ (qj) l_ (rk) l_ (sl) c_ (ijkl)) </Dd> <P> where l are the components of an orthogonal rotation matrix (L). The same relation also holds for inversions . </P> <P> In matrix notation, if the transformed basis (rotated or inverted) is related to the reference basis by </P> <Dl> <Dd> (e i ′) = (L) (e i) (\ displaystyle (\ mathbf (e) _ (i)') = (L) (\ mathbf (e) _ (i))) </Dd> </Dl>

Describe some uses for materials that obey hooke's law