\[ \int \frac {\cosh ^2(x)}{a \cosh (x)+b \sinh (x)} \, dx \]
Optimal antiderivative \[ -\frac {b^{2} \arctan \left (\frac {b \cosh \left (x \right )+a \sinh \left (x \right )}{\sqrt {a^{2}-b^{2}}}\right )}{\left (a^{2}-b^{2}\right )^{\frac {3}{2}}}-\frac {b \cosh \left (x \right )}{a^{2}-b^{2}}+\frac {a \sinh \left (x \right )}{a^{2}-b^{2}} \]
command
integrate(cosh(x)**2/(a*cosh(x)+b*sinh(x)),x)
Sympy 1.10.1 under Python 3.10.4 output
\[ \text {output too large to display} \]
Sympy 1.8 under Python 3.8.8 output \[ \text {Timed out} \]_____________________________________________________