TY - JOUR AU - Брисіна, І. В. AU - Макарічев, В. О. PY - 2016/12/12 Y2 - 2024/03/29 TI - Approximation properties of generalized Fup-functions JF - Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics JA - VKhNU VL - 84 IS - 0 SE - DO - 10.26565/2221-5646-2016-84-06 UR - https://periodicals.karazin.ua/mech_math/article/view/8566 SP - 61-92 AB - Generalized Fup-functions are considered. Almost-trigonometric basis theorem is proved. Spaces of linear combinations of shifts of the generalized Fup-functions are constructed and an upper estimate of the best approximation of classes of periodic differentiable functions by these spaces in the norm of $L_2[-\pi,\pi]$ is obtained. ER -