A system has the transfer function

s + a T(s) = s+63 +12s + 12s +6 Determine the values of a that render the system unobservable. a. a 1.30 or a = -1.43 b. a 3.30 or a = 1.43 c. a -3.30 or a = -1.43 d. a -5.7 or a = -2.04