Does anybody happen to know what the Fourier transform of $f(x) = \sin(x + \sin(x))$ is?
More generally, what is the Fourier transform of $g(x) = \sin(\phi_1 x + \mu \sin(\phi_2 x))$? ($\phi_1$, $\phi_2$ and $\mu$ are constants.)
I'm pretty sure I saw these written down somewhere, but Wolfram|Alpha insists that it cannot determine the result...