Abstract:
For the classes of periodic functions with $r$-th derivative integrable in the mean,we obtain a best quadrature formula of the form \begin{gather*}
\int_0^1f(x)\,dx=\sum_{k=0}^{m-1}\sum_{l=0}^{\rho}p_{k,l}f^{(l)}(x_k)+R(f),\quad0\le\rho\le r-1,
\\
0\le x_0<x_1<\dots<x_m-1\le1,
\end{gather*}
where $\rho=r-2$ and $r-3$, $r=3,5,7,\dots$, and we determine an exact bound for the error of this formula.