\[ -y'(x) \left (a+6 k^2 \sin ^2(x)\right )+b y(x)+y^{(3)}(x)=0 \] ✗ Mathematica : cpu = 0.0414677 (sec), leaf count = 0
, could not solve
DSolve[b*y[x] - (a + 6*k^2*Sin[x]^2)*Derivative[1][y][x] + Derivative[3][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0
, result contains DESol or ODESolStruc
\[y \relax (x ) = \mathit {DESol}\left (\left \{\frac {d^{3}}{d x^{3}}\textit {\_Y} \relax (x )+\left (-6 k^{2} \left (\sin ^{2}\relax (x )\right )-a \right ) \left (\frac {d}{d x}\textit {\_Y} \relax (x )\right )+b \textit {\_Y} \relax (x )\right \}, \left \{\textit {\_Y} \relax (x )\right \}\right )\]