Test Latex
At first, we sample in the ( is odd) equidistant points around :[ f_k = f(x_k),: x_k = x^*+kh,: k=-frac{N-1}{2},dots,frac{N-1}{2}]where is some step.Then we interpolate points by polynomialbegin{equation} label{eq:poly} P_{N-1}(x)=sum_{j=0}^{N-1}{a_jx^j}end{equation}Its coefficients are found as a solution of system of linear equations:begin{equation} label{eq:sys} left{ P_{N-1}(x_k) = f_kright},quad k=-frac{N-1}{2},dots,frac{N-1}{2}end{equation}Here are references to existing equations: (ref{eq:poly}), (ref{eq:sys}).Here is reference to non-existing equation (ref{eq:unknown}). […]