Function vector:cross 
Returns the vector which resulted in the cross product of the two vectors. 
Syntax 
vector:cross(vector vect) 
Returns 
number 
Part of 
ComputerCraft 
API 
vector 
Examples
Example 
Creates a cross product of two vectors and prints the resulting vector. 
Code 
local a = vector.new(1, 2, 3)
local b = vector.new(4, 5, 6)
local c = a:cross(b)
print(c.x)
print(c.y)
print(c.z)
(3)
6
(3)

Example 
Code to recreate the function. Gives insight into what the function does. 
Code 
local a = vector.new(1, 2, 3)
local b = vector.new(2, 1, 2)
local c = vector.new(
(a.y * b.z  a.z * b.y),
(a.z * b.x  z.x * b.z),
(a.x * b.y  a.y * b.x))
c.x = 1
c.y = 4
c.z = 3

It is important to note that a:cross(b) will not usually equal b:cross(a).
More information about cross products can be found at [1]