Symmetrical formulas for rational interpolants (Q788925)

The author presents a symmetrical determinant formula for rational interpolants. (The symmetry is in the visual appearance and similarity between the determinants for denominator and numerator.) It provides a solution to what is sometimes called the linearized rational interpolation problem \((Q(x_ i)f_ i=P(x_ i)\) rather than \(P/Q(x_ i)=f_ i)\). Whether a value \(f_ i\) is actually attained is determined by the nonvanishing of certain cofactors of the denominators.