Difference between revisions of "Derivative of Legendre chi 2"

Proposition: The following formula holds: $$\dfrac{d}{dx} \chi_2(x) = \dfrac{\mathrm{arctanh}(x)}{x},$$ where $\chi$ denotes the Legendre chi function and $\mathrm{arctanh}$ denotes the inverse hyperbolic tangent function.