Covered today: Pieces of sections 3.1, 3.2, and 3.5. We now know (although we haven't proved it yet) the general solution of any 2nd-order homogeneous constant coefficient DE in which the characteristic equation has real roots.

For next time: 3.1 - 1,2,5,10,17,18,21 and 3.2 - 9,12,13 and 3.5 - 2, 14.