Onesided, intertwining, positive and copositive polynomial approximation with interpolatory constraints

German Dzyubenko, Kirill A. Kopotun

Given $k\in N$, a nonnegative function $f\in C^r[a,b]$, $r\ge 0$, an arbitrary finite collection of points $\{{\alpha }_i{\}}_{i\in J}\subset [a,b]$, and a corresponding collection…