\[ y'(x) (x \sin (y(x))-1)+\cos (y(x))=0 \] ✓ Mathematica : cpu = 0.170607 (sec), leaf count = 145
DSolve[Cos[y[x]] + (-1 + x*Sin[y[x]])*Derivative[1][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to -\cos ^{-1}\left (\frac {c_1 x-\sqrt {-x^2+1+c_1{}^2}}{1+c_1{}^2}\right )\right \},\left \{y(x)\to \cos ^{-1}\left (\frac {c_1 x-\sqrt {-x^2+1+c_1{}^2}}{1+c_1{}^2}\right )\right \},\left \{y(x)\to -\cos ^{-1}\left (\frac {\sqrt {-x^2+1+c_1{}^2}+c_1 x}{1+c_1{}^2}\right )\right \},\left \{y(x)\to \cos ^{-1}\left (\frac {\sqrt {-x^2+1+c_1{}^2}+c_1 x}{1+c_1{}^2}\right )\right \}\right \}\] ✓ Maple : cpu = 0.073 (sec), leaf count = 108
dsolve((x*sin(y(x))-1)*diff(y(x),x)+cos(y(x)) = 0,y(x))
\[y \left (x \right ) = \arctan \left (\frac {-c_{1} \sqrt {-x^{2}+c_{1}^{2}+1}+x}{c_{1}^{2}+1}, \frac {c_{1} x +\sqrt {-x^{2}+c_{1}^{2}+1}}{c_{1}^{2}+1}\right )\]