\[ y'(x)+y(x) \cos (x)-e^{-\sin (x)}=0 \] ✓ Mathematica : cpu = 0.023404 (sec), leaf count = 23
\[\left \{\left \{y(x)\to c_1 e^{-\sin (x)}+x e^{-\sin (x)}\right \}\right \}\]
✓ Maple : cpu = 0.007 (sec), leaf count = 19
\[ \left \{ y \left ( x \right ) ={{\rm e}^{-\sin \left ( x \right ) }}{\it \_C1}+{{\rm e}^{-\sin \left ( x \right ) }}x \right \} \]