关于Tchebycheff-Fourier级数的(H,λ)平均的逼近(英文)

On the Approximation by (H,λ) Means of Tchebycheff-Fourier Series

我们定义了(H,λ)求和法,它含有(N,p_n),(R_n~γ)和(V_(mn))求和法。讨论了函数f(x)∈C^r[-1,1](r∈N_0)以及f(x)∈W^rH^a(r∈N_0,0<a<1)的切比晓夫-富里埃级数的逼近阶。

The summability of(H,λ)which contains the summabilities of (N,Pn),(Rnτ) and (Vmn) is defined. The degree of approximation to a function f(x)∈Cτ[-1,1](T∈N。) by(H,λ) means and to a function f(x) ∈Wτ Hσ (τ∈N。, 0<α<1) by (c, β) means of its Tcheb-ycheff-Fourier series is discussed.