Kh. M. Shadimetov

Kh. M. Shadimetov, A. R. Hayotov

In this paper in $W_2^{(m,m-1)}(0,1)$ space the problem of construction of optimal quadrature formula in the sense of Sard is considered and using S.L. Sobolev's method it is obtained new optimal quadrature formula of such type. For the optimal coefficients explicit formulas are obtained. Furthermore, the numerical results which confirm the theoretical results of this work is given.

Kh. M. Shadimetov, A. R. Hayotov, F. A. Nuraliev

In this paper in the space $L_2^{(m)}(0,1)$ the problem of construction of optimal quadrature formulas is considered. Here the quadrature sum consists on values of integrand at nodes and values of first derivative of integrand at the end points of integration interval. The optimal coefficients are found and norm of the error functional is calculated for arbitrary fixed $N$ and for any $m\geq 2$. It is shown that when $m=2$ and $m=3$ the Euler-Maclaurin quadrature formula is optimal.

Kh. M. Shadimetov, A. R. Hayotov

In this paper problem of construction of optimal quadrature formulas in $W_2^{(m,m-1)}(0,1)$ space is considered. Here by using Sobolev's algorithm when $m=1,2$ we find the optimal coefficients of the quadrature formulas of the form $$ \int\limits_0^1ϕ(x)dx\cong \sum\limits_{β=0}^NC_βϕ(x_β). $$

Kh. M. Shadimetov, A. R. Hayotov, N. H. Mamatova

In this paper the problem of construction of lattice optimal interpolation formulas in the space $\widetilde{L_2^{(m)}} (0,1)$ is considered. Using S.L. Sobolev's method explicit formulas for the coefficients of lattice optimal interpolation formulas are given and the norm of the error functional of lattice optimal interpolation formulas is calculated. Moreover, connection between optimal interpolation formula in the space $\widetilde{L_2^{(m)}} (0,1)$ and optimal quadrature formula in this space is shown. Finally, numerical results are given.

Kh. M. Shadimetov

It is discussed the problem on construction of optimal quadrature formulas in the sense of Sard in the space $L_2^{(m)}(0,1)$, when the nodes of quadrature formulas are equally spaced. Here the representations of optimal coefficients for any natural numbers $m$ and $N$ are found.

Kh. M. Shadimetov, A. R. Hayotov

In the paper properties of the discrete analogue $D_m(hβ)$ of the differential operator $\frac{d^{2m}}{dx^{2m}}-\frac{d^{2m-2}}{dx^{2m-2}}$ are studied. It is known, that zeros of differential operator $\frac{d^{2m}}{dx^{2m}}-\frac{d^{2m-2}}{dx^{2m-2}}$ are functions $e^x$, $e^{-x}$ and $P_{2m-3}(x)$. It is proved that discrete analogue $D_m(hβ)$ of this differential operator also have similar properties.

Kh. M. Shadimetov, A. R. Hayotov, F. A. Nuraliev

In the present paper the problem of construction of optimal quadrature formulas in the sense of Sard in the space $L_2^{(m)}(0,1)$is considered. Here the quadrature sum consists of values of the integrand at nodes and values of the first and the third derivatives of the integrand at the end points of the integration interval. The coefficients of optimal quadrature formulas are found and the norm of the optimal error functional is calculated for arbitrary natural number $N$ and for any $m\geq 4$ using S.L. Sobolev method which is based on discrete analogue of the differential operator $d^{2m}/dx^{2m}$. In particular, for $m=4,\ 5$ optimality of the classical Euler-Maclaurin quadrature formula is obtained. Starting from $m=6$ new optimal quadrature formulas are obtained.

Kh. M. Shadimetov

In this paper the discrete analogue $D_m[β]$ of the differential operator $d^{2m}/dx^{2m}$ is constructed and its some new properties are proved.

Kh. M. Shadimetov, A. R. Hayotov

In the Sobolev space $L_2^{(m)}(0,1)$ optimal quadrature formulas with the nodes (1.5) are investigated. For optimal coefficients explicit form are obtained and norm of the error functional is calculated. In particular, by choosing parameter $η_0$ in (1.5) the optimal quadrature formulas with positive coefficients are obtained and compared with well known optimal formulas.