Question Number 222422 by MrGaster last updated on 26/Jun/25
$$\mathrm{Prove}:\int_{\mathrm{0}} ^{+\infty} \frac{{x}^{\mathrm{2}} \mathrm{lnsinh}{x}}{\mathrm{cosh}\:\mathrm{3}{x}}{dx}=\frac{\mathrm{1}}{\mathrm{9}}\pi^{\mathrm{2}} {G}−\frac{\mathrm{5}}{\mathrm{108}}\pi^{\mathrm{3}} \mathrm{ln}\:\mathrm{2} \\ $$