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 (d).

Use the nodes  [Graphics:../Images/NewtonPolyMod_gr_167.gif]  to construct the Newton interpolation polynomial  [Graphics:../Images/NewtonPolyMod_gr_168.gif],  of degree n = 4, and compare it to the polynomial constructed with Mathematica's InterpolatingPolynomial procedure.

[Graphics:../Images/NewtonPolyMod_gr_169.gif]


[Graphics:../Images/NewtonPolyMod_gr_170.gif]
[Graphics:../Images/NewtonPolyMod_gr_171.gif]
[Graphics:../Images/NewtonPolyMod_gr_172.gif]
[Graphics:../Images/NewtonPolyMod_gr_173.gif]

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

[Graphics:../Images/NewtonPolyMod_gr_174.gif]

[Graphics:../Images/NewtonPolyMod_gr_175.gif]

Notice that  [Graphics:../Images/NewtonPolyMod_gr_176.gif]  is obtained from  [Graphics:../Images/NewtonPolyMod_gr_177.gif]  by adding one more term.

[Graphics:../Images/NewtonPolyMod_gr_178.gif]

[Graphics:../Images/NewtonPolyMod_gr_179.gif]

[Graphics:../Images/NewtonPolyMod_gr_180.gif]

[Graphics:../Images/NewtonPolyMod_gr_181.gif]

[Graphics:../Images/NewtonPolyMod_gr_182.gif]

Now graph the function and polynomial, and interpolation nodes.

[Graphics:../Images/NewtonPolyMod_gr_183.gif]

[Graphics:../Images/NewtonPolyMod_gr_184.gif]

[Graphics:../Images/NewtonPolyMod_gr_185.gif]
[Graphics:../Images/NewtonPolyMod_gr_186.gif]
[Graphics:../Images/NewtonPolyMod_gr_187.gif]
[Graphics:../Images/NewtonPolyMod_gr_188.gif]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(c) John H. Mathews 2004