\[ y'(x)=(y(x)+\cos (x))^2+\sin (x) \] ✓ Mathematica : cpu = 0.11646 (sec), leaf count = 18
\[\left \{\left \{y(x)\to -\cos (x)+\frac {1}{-x+c_1}\right \}\right \}\] ✓ Maple : cpu = 0.063 (sec), leaf count = 16
\[ \left \{ y \left ( x \right ) =-\cos \left ( x \right ) + \left ( -x+{\it \_C1} \right ) ^{-1} \right \} \]