Algodoo

Just wondering, what is the point of this scene? I mean what are you demonstrating with it? Also, N2 can be modified but N2 is not in the equation shown. The equation only shows N1 and N-1. Also, why does d change value when N1 or N2 is changed? Is that correct? What is the equation for?

Sorry for all the questions. I'm not very skilled in math so some of my questions may not be valid, so please let me know if I asked any stupid questions. Thanks!

In this scene im trying to contribute in algodoo with some maths.
The equation is a general equation to know an arithmetic serie, e.g:
1,2,3,4... where the diffenrence (d) is in the case of this scene, a1 - a2. In this scene you can calculate the difference with a calculation of aB - a(B+1). And B means the serie number. But, if you wanna know more about this equations just chek this link > http://en.wikipedia.org/wiki/Arithmetic_progression

Sorry if you didn't understand me telling you this ,
Thanks

Okay, now I get it! d is simply the difference between the terms N1 and N2. Sorry for my misunderstanding. I have a fairly good understanding of math concepts, but I struggle with it when it comes time to do the calculations (if that makes any sense).

Thanks!