\[ y'(x) \left (y(x)^2+4 \sin (x)\right )-\cos (x)=0 \] ✓ Mathematica : cpu = 0.246344 (sec), leaf count = 39
\[\text {Solve}\left [-\frac {1}{32} e^{-4 y(x)} \left (8 y(x)^2+4 y(x)+1\right )-e^{-4 y(x)} \sin (x)=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.061 (sec), leaf count = 28
\[\left \{c_{1}+\frac {\left (-8 y \left (x \right )^{2}-32 \sin \left (x \right )-4 y \left (x \right )-1\right ) {\mathrm e}^{-4 y \left (x \right )}}{32} = 0\right \}\]