Cross product of two vectors in Python

Question

How can I calculate the cross product of two vectors without the use of programming libraries?

E.g given vectors a = (1, 2, 3) and b = (4, 5, 6)

Answer 1

If you want to implement the cross product yourself you may see http://en.wikipedia.org/wiki/Vector_cross_product or a math/physics book. Shortly (a1, a2, a3) X (b1, b2, b3) = (a2*b3-a3*b2, a3*b1-a1*b3, a1*b2-a2*b1)