# HW4 Prob 3a formula correction

The formula in the book for problem 4a is incorrect. It should be be replaced with:

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

--Julia Braman 08:19, 23 October 2007 (PDT)