Given a function $1/\sqrt{x^2−k^2}$ where k is a constant with a small imaginary part, how do you go about constructing a rational approximation? I am interested in the $L_p (p=2 \ or\ ∞)$ norm of the difference being small on the real line. Both the theoretical and the practical implementation is of interest.
2026-03-28 23:11:47.1774739507
Approximation of a given function by rational functions
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