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 (c).

Use the nodes  [Graphics:../Images/NewtonPolyMod_gr_146.gif]  to construct the Newton interpolation polynomial  [Graphics:../Images/NewtonPolyMod_gr_147.gif],  of degree n = 3, and compare it to the polynomial constructed with Mathematica's InterpolatingPolynomial procedure.

[Graphics:../Images/NewtonPolyMod_gr_148.gif]


[Graphics:../Images/NewtonPolyMod_gr_149.gif]
[Graphics:../Images/NewtonPolyMod_gr_150.gif]
[Graphics:../Images/NewtonPolyMod_gr_151.gif]
[Graphics:../Images/NewtonPolyMod_gr_152.gif]

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

[Graphics:../Images/NewtonPolyMod_gr_153.gif]
[Graphics:../Images/NewtonPolyMod_gr_154.gif]

Notice that  [Graphics:../Images/NewtonPolyMod_gr_155.gif]  is obtained from  [Graphics:../Images/NewtonPolyMod_gr_156.gif]  by adding one more term.

[Graphics:../Images/NewtonPolyMod_gr_157.gif]

[Graphics:../Images/NewtonPolyMod_gr_158.gif]

[Graphics:../Images/NewtonPolyMod_gr_159.gif]

[Graphics:../Images/NewtonPolyMod_gr_160.gif]

Now graph the function and polynomial, and interpolation nodes.

[Graphics:../Images/NewtonPolyMod_gr_161.gif]

[Graphics:../Images/NewtonPolyMod_gr_162.gif]

[Graphics:../Images/NewtonPolyMod_gr_163.gif]
[Graphics:../Images/NewtonPolyMod_gr_164.gif]
[Graphics:../Images/NewtonPolyMod_gr_165.gif]
[Graphics:../Images/NewtonPolyMod_gr_166.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004