TY - JOUR
AU - S. B. Vakarchuk
AU - M. B. Vakarchuk
PY - 2022/05/31
Y2 - 2022/10/07
TI - $K$-functionals and extreme problems of the theory of approximation for classes of analytic functions in the circle. I
JF - Ukrains’kyi Matematychnyi Zhurnal
JA - Ukr. Mat. Zhurn.
VL - 74
IS - 4
SE - Research articles
DO - 10.37863/umzh.v74i4.6980
UR - http://umj.imath.kiev.ua/index.php/umj/article/view/6980
AB - УДК 517.5Based on the Hadamard composition in the Hardy, Bergman and Gvaradze Banach spaces of functions analytic in the unit circle, we consider a generalization of the $K$-functional. In solving some extreme problems of the theory of approximation in the complex plane, we obtain certain exact results in the case where the indicated $K$-functional is used as a characteristic of smoothness.
ER -