Approximation of the derivative of a function by Fourier coefficients

Title	Approximation of the derivative of a function by Fourier coefficients
Authors	N. D. Kuzmichev¹ ¹National Research Mordovian State University
Annotation	The theorems proof is given according to which the derivative of a function belonging to the Helder-Lipschitz class $C^{alpha
Keywords	the Gelder-Lipschitz class, a harmonically modulated argument, the dependence of the Fourier coefficients, approximation of the derivative of a function.
Citation	Kuzmichev N. D. ''Approximation of the derivative of a function by Fourier coefficients'' [Electronic resource]. Proceedings of the XVII International scientific conference "Differential equations and their applications in mathematical modeling". Saransk: SVMO Publ, 2025. - pp. 140-145. Available at: https://conf.svmo.ru/files/2025/papers/paper28.pdf. - Date of access: 07.12.2025.