PARTIAL DIFFERENTIAL EQUATIONS
web.math.ucsb.edu › ~grigoryan › 124Avariable x, the dependent variable uand derivatives of uis called an ordinary di erential equation. Some examples of ODEs are: u0(x) = u u00+ 2xu= ex u00+ x(u0)2 + sinu= lnx In general, and ODE can be written as F(x;u;u0;u00;:::) = 0. In contrast to ODEs, a partial di erential equation (PDE) contains partial derivatives of the depen-
Partial Differential Equations
math.iitm.ac.in › caimna › pdeLinear PDE:If the dependent variable and all its partial derivatives occure linearly in any PDE then such an equation is called linear PDE otherwise a non-linear PDE. In the above example equations 6.1.1, 6.1.2, 6.1.3 & 6.1.4 are linear whereas 6.1.5 & 6.1.6 are non-linear. Quasi-linear PDE:A PDE is called as a quasi-linear if all the terms with highest order derivatives of dependent variables occur linearly, that is ...