# Math Help - numerical analysis

1. ## numerical analysis

How do I show that for any x0 < x1 < x2 < ... < xn, the fundamental Lagrange polynomials satisfy

(the summation from j = 0 to n of lj(x)) = 1
where lj(x) is the jth fundamental Lagrange polynomial of degree n ?

I've been trying to work this out algebraically, but I don't really know where to start. Thanks for any help.

2. I did the same problem about 6 months ago. If I remember well, you have to use the definition of Lagrange polynomial : check out Lagrange polynomial - Wikipedia, the free encyclopedia.
I have no time to help you more (so sorry about that), but in
(the summation from j = 0 to n of lj(x)) = 1
where lj(x) is the jth fundamental Lagrange polynomial of degree n ?
, don't you mean the product instead of the summation?