THE CONVERGENCE ORDER OF THE INTERPOLATION PROCESS BY LAGRANGE POLYNOMIALS

Let f(x) be an arbitrary continuous function on -1, 1] and letus denote T_n(x)=cos nθ, x=cos θ,T_n(x) is to be known as the first kind of Chebyshev polynomial ofdegree n. The zeros. of T_n(x) are