\[ y'(x) \left (y(x)^2+4 \sin (x)\right )-\cos (x)=0 \] ✓ Mathematica : cpu = 0.109515 (sec), leaf count = 32
\[\text {Solve}\left [-\frac {1}{32} e^{-4 y(x)} \left (8 y(x)^2+4 y(x)+32 \sin (x)+1\right )=c_1,y(x)\right ]\]
✓ Maple : cpu = 0.058 (sec), leaf count = 28
\[ \left \{ {\frac { \left ( -8\, \left ( y \left ( x \right ) \right ) ^{2}-4\,y \left ( x \right ) -32\,\sin \left ( x \right ) -1 \right ) {{\rm e}^{-4\,y \left ( x \right ) }}}{32}}+{\it \_C1}=0 \right \} \]