Calculate Constrained Optimization by Using Lagrangian - Mathematica Stack Exchange
Euler–Lagrange equation - Wikipedia
SOLVED: 1 Show that fn (xi) = f(xi) for all interpolations using Lagrange polynomials, i.e x - Xj fn(xi) = Li(x)f(xi) = f(xi), where Li(x) = Xi - Xj i=0 j=0,j#i 2