Hi Guys,This is a Smart Worksheet on second order linear differential equations covering both homogeneous and non-homogeneous types and including problems with initial conditions.There are also some useful de solver tools where you can type in your own problems and obtain the worked solutions so you can check any homework that you have.There's a PDF file for those who want to work on the sheet independently and an email math que, where you can jot down a questions and append it to an email. If I get time, I will write up a YouTube video solution and send you the link.All the best with the worksheet and if you have any feedback just give us a buzz.Cheers,Mark

修复了一些BUG。