Suppose I have f(x)=Sx/||x||, where S is a n×n positive definite symmetric matrix and x is a vector of length n. I'd like to know the antiderivative of f(x), which is a real-valued …

The question here is sparked by the discussion inside this question about indefinite sum(antidifference) of tan(x). A proposed solution was a function $$f_1(x)=ix-\psi _{e^{2 i}} …