2. Method of Characteristics
www.math.ualberta.ca › ~xinweiyu › 436The above understanding leads to the following “method of characteristics” due to Lagrange. Theorem 2.5. The general solution of a first-order, quasi-linear PDE a(x,y,u) u x + b(x,y,u) u y = c(x,y,u) (2.39) satisfies F(Φ,Ψ)=0, (2.40) where Fis an arbitrary function of Φ(x,y,u) and Ψ(x,y,u), and any intersection of the level sets of Φ
Method of Characteristics
www.iist.ac.in › sites › defaultPDE and the initial condition. The reduction of a PDE to an ODE along its characteristics is called the method of characteristics. The solution of PDE (1a) corresponds to transporting the initial profile F(x) unaltered (preserving the shape of initial waveform) along the characteristics with a speed dx/dt =a (see figure 1).