y'(x)^3 \left(f'(x) y'(x)+f(x) y''(x)\right)-y''(x) \left(f''(x) y'(x)+2 f'(x) y''(x)+f(x) y^{(3)}(x)\right)+y'(x) \left(f^{(3)}(x) y'(x)+3 f''(x) y''(x)+3 y^{(3)}(x) f'(x)+f(x) y^{(4)}(x)\right)+\cos (y(x)) \left(q(x) y''(x)-q'(x) y'(x)\right)+2 q(x) y'(x)^2 \sin (y(x))=0