Lagrange Polynomial

The lowest degree polynomial that Interpolates a set of data

Formula

$l_j(x)=\frac{(x-x_0)\dots (x-x_{j-1})(x-x_{j+1})\dots (x-x_k)}{(x_j-x_0)\dots (x_j-x_{j-1})(x_j-x_{j+1})\dots (x_j-x_k)}$