Consider the following state-space model: ? = ?? ?? ? = ?? a- Is the mode controllable and/or observable with the following matrices? ? = [ 0 1 8 6], ? = [0 0 1 1], ? = [ 2 1 4 2] b- Compute the observer canonical form of the following systems. Please explain if you cannot compute that for any of the following. i) ? = [5 0 0 4], ? = [1 1], ? = [1 1] ii) ? = [5 0 0 4], ? = [1 0], ? = [1 0]