$$3 x^{2} \cosh{\left(x^{3} \right)}$$
/ / 3\ 3 / 3\\
3*x*\2*cosh\x / + 3*x *sinh\x //
$$3 x \left(3 x^{3} \sinh{\left(x^{3} \right)} + 2 \cosh{\left(x^{3} \right)}\right)$$
/ / 3\ 6 / 3\ 3 / 3\\
3*\2*cosh\x / + 9*x *cosh\x / + 18*x *sinh\x //
$$3 \left(9 x^{6} \cosh{\left(x^{3} \right)} + 18 x^{3} \sinh{\left(x^{3} \right)} + 2 \cosh{\left(x^{3} \right)}\right)$$