Abstract:
For the classes of periodic functions with r-th derivative integrable in the mean,we obtain a best quadrature formula of the form ∫10f(x)dx=m−1∑k=0ρ∑l=0pk,lf(l)(xk)+R(f),0⩽ρ⩽r−1,0⩽x0<x1<⋯<xm−1⩽1,
where ρ=r−2 and r−3, r=3,5,7,…, and we determine an exact bound for the error of this formula.