scholarly journals A Characterization of Smoothness in Terms of Approximation by Algebraic Polynomials in LP

1995 ◽  
Vol 81 (1) ◽  
pp. 13-22 ◽  
Author(s):  
V.A. Operstein
2013 ◽  
Vol 21 ◽  
pp. 3
Author(s):  
T.A. Agoshkova

In the space $L_{\psi}[-1;1]$ of non-periodic functions with metric $\rho(f,0)_{\psi} = \int\limits_{-1}^1 \psi(|f(x)|)dx$, where $\psi$ is a function of the type of modulus of continuity, we study Jackson inequality for modulus of continuity of $k$-th order in the case of approximation by algebraic polynomials. It is proved that the direct Jackson theorem is true if and only if the lower dilation index of the function $\psi$ is not equal to zero.


2000 ◽  
Vol 36 (3-4) ◽  
pp. 353-358 ◽  
Author(s):  
S. Pawelke

We con ider the best approximation E (n,f)by algebraic polynomials of degree at most n for function f in L 1 (-1, 1)or C [-1, 1]and give imple necessary and u .cient condition for E (n,f)=O (n-.),n ›.,u ing the well-known results in the ca e of ap- proximation of periodic function by trigonometric polynomials.


Sign in / Sign up

Export Citation Format

Share Document