How to show the Upper bound of error for n-th order degree polynomial interpolation of f ?

4. We know that the error for n-th degree polynomial interpolation of f, Rn(x) = f(x) - Pn(x) = f(n+?)(2) ? (x - x;) given the interpolation points {ri}?_o. Assume that Xitl - Xi = h for i = (n+1 )! 0, ...,n - 1. Prove that | Run(20) |5 hn+1 max 4 (n + 1) SE[a,b] ( f ( 2 + 1 ) ( 8 )