A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z).

If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would represent a point in the region,   and a vector from the origin to the point.

Given the vectors:

        A = (a1,  a2,  a3) 
        B = (b1,  b2,  b3) 
        C = (c1,  c2,  c3) 

then the following common vector products are defined:

 The dot product       (a scalar quantity)
  A • B = a1b1   +   a2b2   +   a3b3  
 The cross product       (a vector quantity)
  A x B = (a2b3  -   a3b2,     a3b1   -   a1b3,     a1b2   -   a2b1)  
 The scalar triple product       (a scalar quantity)
  A • (B x C) 
 The vector triple product       (a vector quantity)
  A x (B x C) 


Task

Given the three vectors:

        a = ( 3,    4,    5)
        b = ( 4,    3,    5)
        c = (-5,  -12,  -13)

 Create a named function/subroutine/method to compute the dot product of two vectors.
 Create a function to compute the cross product of two vectors.
 Optionally create a function to compute the scalar triple product of three vectors.
 Optionally create a function to compute the vector triple product of three vectors.
 Compute and display: a • b
 Compute and display: a x b
 Compute and display: a • (b x c), the scalar triple product.
 Compute and display: a x (b x c), the vector triple product.


References

   A starting page on Wolfram MathWorld is   Vector Multiplication .
   Wikipedia   dot product. 
   Wikipedia   cross product. 
   Wikipedia   triple product.


Related tasks

   Dot product
   Quaternion type


go =>
  A = [3, 4, 5],
  B = [4, 3, 5],
  C = [-5, -12, -13],
 
  println(a=A),
  println(b=B),
  println(c=C),
  println("A . B"=dot(A,B)),
  println("A x B"=cross(A,B)),
  println("A . (B x C)"=scalar_triple(A,B,C)),
  println("A X (B X C)"=vector_triple(A,B,C)), 
  nl.
 
dot(A,B)   = sum([ AA*BB : {AA,BB} in zip(A,B)]).
cross(A,B) = [A[2]*B[3]-A[3]*B[2], A[3]*B[1]-A[1]*B[3], A[1]*B[2]-A[2]*B[1]].
 
scalar_triple(A,B,C) = dot(A,cross(B,C)).
vector_triple(A,B,C) = cross(A,cross(B,C)).