The first derivative
[src]
$$3 \tanh^{2}{\left(3 x - 1 \right)} - 3$$
The second derivative
[src]
/ 2 \
-18*\-1 + tanh (-1 + 3*x)/*tanh(-1 + 3*x)
$$- 18 \left(\tanh^{2}{\left(3 x - 1 \right)} - 1\right) \tanh{\left(3 x - 1 \right)}$$
The third derivative
[src]
/ 2 \ / 2 \
54*\-1 + tanh (-1 + 3*x)/*\-1 + 3*tanh (-1 + 3*x)/
$$54 \left(\tanh^{2}{\left(3 x - 1 \right)} - 1\right) \left(3 \tanh^{2}{\left(3 x - 1 \right)} - 1\right)$$