how to do crosss product code example

Example: cross product

Let a be a vector with coordinates (a1, a2, a3)
Let b be a vector with coordinates (b1, b2, b3)

Cross Product for 3x3 Matrices:
<a1, a2, a3> × <b1, b2, b3> = 
<a2*b3 - a3*b2,
a3*b1 - a1*b3,
a1*b2 - a2*b1>

a × b = |a||b|sinθ, where θ is the angle between the two vectors and n is the
					unit vector perpendicular to the plane created by a and b