The last example on my homework assignment this week is this: Solve the following differential equation.
y'' + 2y' + y = e^{-x}
I started by solving it like it was y'' + 2y' +y = 0 (Instert y = e^ax and so on) and got the following equation and solution:
e^{ax}(a^2 + 2a + 1) = 0 => a...