Recurrence Relations and Characteristic Equations

Question

I am not understanding how to go from the beginning of a recurrence relation to the end. I do not understand how to get to the characteristic equation. I can factor it if I know where it comes from.

Thank you.

Answer 1

I got it from the video! to get the characteristic equation you use an=x^2 term an-1=x term and the an-2= constant term. Then you can factor for the roots.

Answer 2

Look here: http://www.math.upenn.edu/~wilf/DownldGF.html

The downloadable book at this site, Generatingfunctionology, will tell you more than you need to know.