Take the following series D.
2
5
6
12
I then need to make a new column(and make it a matrix) to subtract the values of the previous like so
2, 3
5, 1
6, 6
12,
until eventually
2, 3, 2, 3
5, 1, 5
6, 6
12,
As you can see the result(r) is 3, given that the series could be of any size what formula would always return the last number. I also couldn't figure out how to use the MathJax with matrices. A one line formula would be very nice something like.
r = ??? D ???