In the present paper, we give the explicit formula of the principal part of ∑k=0^n({k}q-[n]qx)^sxk ∏m=0^n-k-1(1-q^mx) with respect to [n]q for any integer s and q ∈ (0, 1]. And, using the expressions, we obtai...In the present paper, we give the explicit formula of the principal part of ∑k=0^n({k}q-[n]qx)^sxk ∏m=0^n-k-1(1-q^mx) with respect to [n]q for any integer s and q ∈ (0, 1]. And, using the expressions, we obtain saturation theorems for Bn (f , qn,x) approximating to f(x) ∈ C[O, 1], 0 〈 qn ≤ 1, qn → 1.展开更多
We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1-x^2)cosnarccosx. By using a decomposition for f(x) ∈ C^τC^τ+1 we obtain an estimate of ‖f(x) -Ln+2(f, ...We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1-x^2)cosnarccosx. By using a decomposition for f(x) ∈ C^τC^τ+1 we obtain an estimate of ‖f(x) -Ln+2(f, x)‖ which reflects the influence of the position of the x's and ω(f^(r+1),δ)j,j = 0, 1,... , s,on the error of approximation.展开更多
基金Supported by the National Natural Science Foundation (10601065)
文摘In the present paper, we give the explicit formula of the principal part of ∑k=0^n({k}q-[n]qx)^sxk ∏m=0^n-k-1(1-q^mx) with respect to [n]q for any integer s and q ∈ (0, 1]. And, using the expressions, we obtain saturation theorems for Bn (f , qn,x) approximating to f(x) ∈ C[O, 1], 0 〈 qn ≤ 1, qn → 1.
基金Supported by the National Nature Science Foundation.
文摘We study some approximation properties of Lagrange interpolation polynomial based on the zeros of (1-x^2)cosnarccosx. By using a decomposition for f(x) ∈ C^τC^τ+1 we obtain an estimate of ‖f(x) -Ln+2(f, x)‖ which reflects the influence of the position of the x's and ω(f^(r+1),δ)j,j = 0, 1,... , s,on the error of approximation.