InterpolatingPolynomial
InterpolatingPolynomial[data, var] gives a polynomial in the variable var which provides an exact fit to a list of data.
The data can have the forms 

, 
, 
, 
, ...
or 
,
, ...
, where in the second case, the
are taken to have values 1, 2, ... .
The
can be replaced by 
,
,
, ...
, specifying derivatives at the points
.
With a list of data of length
, InterpolatingPolynomial gives a polynomial of degree
.
Example: InterpolatingPolynomial[
4, 5, 8
, x]
.
InterpolatingPolynomial gives the interpolating polynomial in Newton form, suitable for numerical evaluation.
See The Mathematica Book on the web: Section 3.3.4 and Section 3.8.1.
See also: Fit, Roots.
Further Examples