Formula_21281

\[\begin{gathered}\left|f(x)-\sum_{k=0}^{n} a_{k} \hat{P}_{k}(x ; \alpha, \beta)\right| \leqslant \frac{c_{2}}{n^{p+\gamma}} n^{q+\frac{1}{2}}, \\x \in[-1,1],\end{gathered}\]