Example 1.   Form the Newton polynomials of degree  n = 1,2, 3, 4, and 5  for the function  [Graphics:Images/NewtonPolyMod_gr_109.gif]  over the interval  [Graphics:Images/NewtonPolyMod_gr_110.gif]  using equally spaced nodes selected from the following list  
[Graphics:Images/NewtonPolyMod_gr_111.gif]  
Solution 1 (b).

Use the nodes  [Graphics:../Images/NewtonPolyMod_gr_126.gif]  to construct the Newton interpolation polynomial  [Graphics:../Images/NewtonPolyMod_gr_127.gif],  of degree n = 2, and compare it to the polynomial constructed with Mathematica's InterpolatingPolynomial procedure.

[Graphics:../Images/NewtonPolyMod_gr_128.gif]


[Graphics:../Images/NewtonPolyMod_gr_129.gif]
[Graphics:../Images/NewtonPolyMod_gr_130.gif]
[Graphics:../Images/NewtonPolyMod_gr_131.gif]
[Graphics:../Images/NewtonPolyMod_gr_132.gif]

The polynomial obtained with Mathematica's InterpolatingPolynomial procedure is the nested form of the Newton polynomial.

[Graphics:../Images/NewtonPolyMod_gr_133.gif]

[Graphics:../Images/NewtonPolyMod_gr_134.gif]

Notice that  [Graphics:../Images/NewtonPolyMod_gr_135.gif]  is obtained from  [Graphics:../Images/NewtonPolyMod_gr_136.gif]  by adding one more term.

[Graphics:../Images/NewtonPolyMod_gr_137.gif]

[Graphics:../Images/NewtonPolyMod_gr_138.gif]
[Graphics:../Images/NewtonPolyMod_gr_139.gif]

Now graph the function and polynomial, and interpolation nodes.

[Graphics:../Images/NewtonPolyMod_gr_140.gif]

[Graphics:../Images/NewtonPolyMod_gr_141.gif]

[Graphics:../Images/NewtonPolyMod_gr_142.gif]
[Graphics:../Images/NewtonPolyMod_gr_143.gif]
[Graphics:../Images/NewtonPolyMod_gr_144.gif]
[Graphics:../Images/NewtonPolyMod_gr_145.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004