4.26. Consider the system of Figure P4.25 with h(t) = ae-u(t), a > 0. This is a low-pass system. (a) The input is x (t) sin² (2t). Find y(t). Notice that the higher frequency components are attenuated more than the lower frequency components. (b) Repeat Part (a) with a = 2 and x(t) = 10 + 5 cos (2t) + 5 cos (8t). Notice how much more the highest frequency component is attenuated relative to the lower frequency components.