It is important to remember that differential equations have been studied by a great many people over the last 300 years, and during most of that time there were no TVs, no cell phones, and no Internet. Given 300 years with nothing else to do, you might get quite adept at changing variables.

- from *Differential Equations* by Paul Blanchard, Robert Devaney, and Glen Hall

# Fall 2012

# Fall 2011

Math 246: Differential Equations for Scientists and Engineers