In Mathematica 8
NDSolve[{x[t] == 1, x[0] == 1}, x[t], {t, 0, 10}]
solves fine and returns
{{x[t]->InterpolatingFunction[{{0.,10.}},<>][t]}}
while Mathematica 9 raises
NDSolve::derivs: No derivatives of dependent variables were found in the equations. NDSolve is designed to solve differential or differential algebraic equations. Use NSolve or FindRoot to numerically solve algebraic equations. >>
I get the point, but is there maybe a way to restore the old behavior via NDSolve
's options system?
f[x,y[x]]==0
, which cannot be solved by any other built-in methods. $\endgroup$