Pointwise estimation of an almost copositive approximation of continuous functions by algebraic polynomials

• Date: 2017
• Main Authors: Dzyubenko, H. A., Дзюбенко, Г. А.
• Format: Article
• Language: Ukrainian
• Published: Institute of Mathematics, NAS of Ukraine 2017
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/1723
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

In the case where a function continuous on a segment $f$ changes its sign at $s$ points $y_i : 1 < y_s < y_{s-1} < ... < y_1 < 1$, for any $n \in N$ greater then a constant $N(k, y_i)$ that depends only on $k \in N$ and \$\min_{i=1,...,s-1}\{ y_i - y_{i+1}\}$, we...