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It may also
be noted for calculating the higher order divided differences we
have used lower order divided differences. In fact starting from
the given zeroth order differences ;
one can
systematically arrive at any of higher order divided differences.
For clarity the entire calculation may be depicted in the form of a
table called
Newton Divided Difference Table.
Again suppose that we are given the data set
and that we are interested in finding the
order Newton Divided Difference interpolynomial. Let us first
construct the Newton Divided Difference Table. Wherein one can
clearly see how the lower order differences are used in
calculating the higher order Divided Differences:
i | 0 | 1 | 2 | 3 | 4 |
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0 | 1 | 2 | 3 | 4 |
![]() |
0 | 1 | 8 | 27 | 64 |
Solution:
Here . One can fit a fourth order Newton
Divided Difference interpolation polynomial to the given data. Let
us generate Newton Divided Difference Table; as requested.
Note: One may note that the given data corresponds to
the cubic polynomial . To fit such a data
order
polynomial is adequate. From the Newton Divided Difference table
we notice that the fourth order difference is zero. Further the
divided differences in the table can be directly used for
constructing the Newton Divided Difference interpolation
polynomial that would fit the data.
Exercise: Using Newton divided difference interpolation polynomial , construct polynomials of degree two and three for the following data:
(1) f(8.1) = 16.94410, f(8.3)=17.56492 , f(8.6) = 18.50515, f(8.7) = 18.82091.
Also approximate f(8.4).
(2) f(0.6) = -0.17694460 , f(0.7) = 0.01375227 , f(0.8) = 0.22363362 , f(1.0) = 0.65809197.
Also approximate f(0.9).