1. The problem statement, all variables and given/known data Find a third order, linear, homogeneous DE which has the following solutions: e[itex]\pi[/itex]t, te[itex]\pi[/itex]t and e-t 2. Relevant equations Standard form of a third-order linear homogenous ODE: Ay''' + By'' + Cy' + Dy = 0 3. The attempt at a solution I tried deriving the characteristic equation given the r values of the solutions. For e[itex]\pi[/itex]t: r = [itex]\pi[/itex], therefore one part of the equation is (r - [itex]\pi[/itex]) For e-t: r = -1, therefore another part of the equation is (r+1) But I can't figure out what to do for the second one.