x*tanh(x) - 1
/ 2 \ x*\1 - tanh (x)/ + tanh(x)
/ 2 / 2 \ \ 2*\1 - tanh (x) + x*\-1 + tanh (x)/*tanh(x)/
/ 2 \ / / 2 \ 2 \ 2*\-1 + tanh (x)/*\3*tanh(x) - x*\-1 + tanh (x)/ - 2*x*tanh (x)/