41.1 Problem number 206

$$\int \frac{1}{\sqrt{1-{\tanh }^2(x)}}dx$$

Optimal antiderivative $$\frac{\tanh \left(x\right)}{\sqrt{\mathrm{sech}{\left(x\right)}^2}}$$

command

integrate(1/(1-tanh(x)**2)**(1/2),x)

Sympy 1.10.1 under Python 3.10.4 output

$$\int \frac{1}{\sqrt{1-{\tanh }^2\left(x\right)}}dx$$

Sympy 1.8 under Python 3.8.8 output

$$\frac{\tanh \left(x\right)}{\sqrt{1-{\tanh }^2\left(x\right)}}$$