About approximation multinominals, orthogonal on any grids

In this work are investigated approximation properties of multinominals $\hat p_n(x)$, orthogonal with weight $\Delta t_j$ on the any grids consisting of final number of points of a piece $[-1,1]$. Namely the approximation formula, in which is established at increase $n$ together with $N$, approximation behaviour of these multinominals close to approximation behaviour of multinominals Lasiandra.