Difference Equation Coefficients

[mad_monkey_j]

Homework Statement

Work out the correct coefficient arrays for these equations:

y(n)=y(n-1)+\frac{1}{5}(x(n)-x(n-5))

y(n) = 0.82y(n -1) + .28x(n)

Homework Equations

\sum a(r)y(n+1-r)=\sum b(k)y(n+1-k) where a(1) = 1


The Attempt at a Solution

Ok for the second equation the coefficients are clearly 0.82 and 0.28, now if I were to put that in an array for MATLAB would it be [0.82 0 0 0 0] and [0.28 0.28 0.28 0.28 0.28]?

For the first equation I have no idea how to go about finding the coefficients.

Cheers for any help.

 

[HallsofIvy]

I think it would be helpful to you to start by determining exactly what the "variables" in this problem are. That is, what will the coefficient matrix be multiplying and what result should that matrix multiplication give?