Problem 3a -- Formula correction

The formula given in problem 3a is incorrect. It should be be replaced with:

\( y_k = C A^k x_0 + \sum_{i=0}^{k-1} C A^i B u_{k-1-i} + D u_k \)

--Mary Dunlop 19:29, 17 October 2006 (PDT)