Consider a system described by the coupled difference equation
y(k + 2) - ν(k) = 0
ν(k + 1) + y(k + 1) = u(k)
where u(k) is the system input.
(a) Find a state-variable formulation for this system. Consider the outputs to be y(k + 1) and ν(k).
(b) Repeat part (a) with y(k) and ν(k) as the outputs.