Maths for Engineers - 3

Lagranges Interpolation

Lagranges Interpolation:

Let f (x0), f (x1), ..., f (xn) be n 1 entries of a function y = f (x), where f (x) is assumed too be polynomial corresponding to the arguments x0, x1, ...,xn.

The polynomial f (x) may be written as;

          

where A0,A1, ...,An are constants to be determined.

Putting x = x0

       

Putting x = x1

  

Similarly,

        

Hence, on substituting the constants values, we get

This result is known as Lagrange’s Interpolation Formula.