PARTIAL DIFFERENTIAL EQUATIONS
web.math.ucsb.edu › ~grigoryan › 124AThere are a number of properties by which PDEs can be separated into families of similar equations. The two main properties are order and linearity. Order. The order of a partial di erential equation is the order of the highest derivative entering the equation. In examples above (1.2), (1.3) are of rst order; (1.4), (1.5), (1.6) and (1.8) are ...