\fTheorem 7. Let f E H (or a linear combination of Dirac delta functions). The solution to (4) can be expressed as yh + yp, where yn is the zero-input solution, that is, the homogeneous solution to (4) (with the same initial conditions), and yp = 5 * f is the zero-state solution given by convolution of the unit impulse response function & and the input function f