Hello,

Its been a long time since I've done PDE's or even ODE's for that matter, and I'm quite rusty. Could anyone please help me with the following?

Solve the following PDE and explain why inverting the equations for $\displaystyle x(s, t)$ and $\displaystyle y(s,t)$ may cause problems:

$\displaystyle u_x + u_y = u$ subject to $\displaystyle u(x, ax) = F(x) $

Find the Jacobian of the coordinate transform to determine when the transformation is invertible.