Find the 95%-signal-energy bandwidth for a given signal e^-at u(t), expressed in Hz. For an input signal x(t) = cos(t), demonstrate that 3 different LTI systems with impulse responses h_1(t) = u(t), h_2(t) = – 2 delta (t) + 5e ^-2t u(t), and h_3(t) = 2te^-t u(t) all produce the same output signal.