- #1
HMPARTICLE
- 95
- 0
$\text{Let } L_{n,i}, i = 0,...,n, \text{be the Lagrange nodal basis at} x_0 < x_1<...<x_n$. Show that, for any polynomial $q \in P_n$
$$\sum_{i=0}^nq(x_i)L_{n,i}(x)= q(x)$$
I don't know how to begin this proof. I know what a lagrange polynomial is, but I am not sure how to begin. If someone could give me a point to start please.
$$\sum_{i=0}^nq(x_i)L_{n,i}(x)= q(x)$$
I don't know how to begin this proof. I know what a lagrange polynomial is, but I am not sure how to begin. If someone could give me a point to start please.