³ The actual formula for the solution to non-homogenous equations is y = e^-I∫ e^Ib(t)dt +ke^-I, where I = ∫ a(t)dt. Note that if b(t) = 0, the first half of this equation disappears (thus illustrating why homogenous equations are easier). It also puts us in a position to deliver a final smackdown to our soothsayer from section 6.3.1. He correctly identified the first part of this formula, but not the second. In general, 1+ke^t is a solution for any value of k, including 0.