a´b= (axi + ayj + azk)×( bxi + byj + bzk)= ax bx i× i + ax by i× j + ax bz i ×k +
+ay bx j×i + ay by j×j + ay bz j×k + az bx k×i + az by k× j + az bz k×k=
= ax by k – ax bz j- -ay bx k+ ay bz i+ az bx j - az by i=
= i(ay bz - azby )- j( ax bz - az bx)+ k(ax by - ay bx )=
=i- j+ k.
.