First of all, you seemed to have typed the problem wrong. All of the terms have Xn? Or maybe you forgot parenthesis?
Why don't you show us what you did, and we can point out where you went wrong.
No they all have Xn in them..
Ok...em I don't know how to do all the symbols and stuff on this so hopefully it'll be ok to read..
I'm gona use % instead of lambda
I let Xn+2-6Xn+1+9Xn=0
Roots at %+/- =3
Then, just following his example I said general solution is of the form
Un=%+n, Un=z%+n (those +n's are subscript, and z is alpha in the notes)
From that i said Un=z%+n + j%-n (where z,j are alpha and beta)
And that's all not right...
First of all, look at the Latex tutorial in the Latex subforum to learn Latex. You can also double click on any formula to see how it is written in Latex.
Characteristic equation is:
You actually have a double root .
How does the solution look like when you have a double root?