<Dd> a = (a x a y a z), b = (b x b y b z), c = (c x c y c z) (\ displaystyle \ mathbf (a) = (\ begin (bmatrix) a_ (x) \ \ a_ (y) \ \ a_ (z) \ end (bmatrix)), \ mathbf (b) = (\ begin (bmatrix) b_ (x) \ \ b_ (y) \ \ b_ (z) \ end (bmatrix)), \ mathbf (c) = (\ begin (bmatrix) c_ (x) \ \ c_ (y) \ \ c_ (z) \ end (bmatrix))) </Dd> <Dl> <Dd> a x = b y c z − b z c y (\ displaystyle a_ (x) = b_ (y) c_ (z) - b_ (z) c_ (y)) </Dd> <Dd> a y = b z c x − b x c z (\ displaystyle a_ (y) = b_ (z) c_ (x) - b_ (x) c_ (z)) </Dd> <Dd> a z = b x c y − b y c x . (\ displaystyle a_ (z) = b_ (x) c_ (y) - b_ (y) c_ (x).) </Dd> </Dl> <Dd> a x = b y c z − b z c y (\ displaystyle a_ (x) = b_ (y) c_ (z) - b_ (z) c_ (y)) </Dd> <Dd> a y = b z c x − b x c z (\ displaystyle a_ (y) = b_ (z) c_ (x) - b_ (x) c_ (z)) </Dd>

F two vectors point in opposite directions their cross product must be zero