$$3 e^{\cosh{\left(3 x \right)}} \sinh{\left(3 x \right)}$$
/ 2 \ cosh(3*x)
9*\sinh (3*x) + cosh(3*x)/*e
$$9 \left(\sinh^{2}{\left(3 x \right)} + \cosh{\left(3 x \right)}\right) e^{\cosh{\left(3 x \right)}}$$
/ 2 \ cosh(3*x)
27*\1 + sinh (3*x) + 3*cosh(3*x)/*e *sinh(3*x)
$$27 \left(\sinh^{2}{\left(3 x \right)} + 3 \cosh{\left(3 x \right)} + 1\right) e^{\cosh{\left(3 x \right)}} \sinh{\left(3 x \right)}$$