Mathematica 9 just does not output anything when i try to solve it using DSolve with or without initial/boundary values. please help
the code is
z := u[x, y];
p := D[u[x, y], x];
q := D[u[x, y], y];
eqn = y*p + (x^3 + x - z)*q == z^2 + z;
sol = DSolve[{eqn, u[0, 0] == 0}, u[x, y], {x, y}]