\[ y^{(3)}(x)-\sin (x) y''(x)-2 \cos (x) y'(x)+y(x) \sin (x)-\log (x)=0 \] ✓ Mathematica : cpu = 2.40225 (sec), leaf count = 64
DSolve[-Log[x] + Sin[x]*y[x] - 2*Cos[x]*Derivative[1][y][x] - Sin[x]*Derivative[2][y][x] + Derivative[3][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to e^{-\cos (x)} \int _1^x\frac {1}{4} e^{\cos (K[1])} \left (2 \log (K[1]) K[1]^2-3 K[1]^2+4 c_1 K[1]+4 c_2\right )dK[1]+c_3 e^{-\cos (x)}\right \}\right \}\] ✓ Maple : cpu = 0.082 (sec), leaf count = 36
dsolve(diff(diff(diff(y(x),x),x),x)-diff(diff(y(x),x),x)*sin(x)-2*cos(x)*diff(y(x),x)+y(x)*sin(x)-ln(x)=0,y(x))
\[y \left (x \right ) = \left (c_{3}+\int \left (2 c_{1} x +c_{2}-\frac {3 x^{2}}{4}+\frac {x^{2} \ln \left (x \right )}{2}\right ) {\mathrm e}^{\cos \left (x \right )}d x \right ) {\mathrm e}^{-\cos \left (x \right )}\]