a) $(\overset{\rightharpoonup}{i}+\overset{\rightharpoonup}{j})\times \overset{\rightharpoonup}{k}$ b) $(\overset{\rightharpoonup}{i}\times\overset{\rightharpoonup}{j})\times \overset{\rightharpoonup}{k}$
c) $(\overset{\rightharpoonup}{i}\times\overset{\rightharpoonup}{k})\cdot\overset{\rightharpoonup}{j}$ č) $\overset{\rightharpoonup}{k}\times (\overset{\rightharpoonup}{i}-\overset{\rightharpoonup}{j})$
Dokaži, da je $(\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b})\times (\overset{\rightharpoonup}{a}+\overset{\rightharpoonup}{b})=2\overset{\rightharpoonup}{a}\times\overset{\rightharpoonup}{b}$.