Page 37 - Foundations Of Differential Calculus
P. 37

20    1. On Finite Differences
        29. If we carefully observe the sums of the powers of x that we have found,
        the first, second, and third terms, we quickly discover the laws of formation
        that they follow. The law for the following terms is not so obvious that we
                                               n
        can state in general the sum for the power x . Later (in paragraph 132 of
        the second part) we will show that

                  x n+1    1  n   1  nω  n−1   1 n (n − 1) (n − 2) ω 3  n−3
             n
          Σx =           − x +     ·    x    −   ·                 x
                 (n +1) ω  2      2 2 · 3      6      2 · 3 · 4 · 5
                                                  5
                  1 n (n − 1) (n − 2) (n − 3) (n − 4) ω  n−5
                +   ·                              x
                  6           2 · 3 · 4 · 5 · 6 · 7
                   3  n (n − 1) ··· (n − 6) ω 7  n−7
                −    ·                    x
                  10       2 · 3 ··· 8 · 9
                                        9
                  5 n (n − 1) ··· (n − 8) ω  n−9
                +   ·                    x
                  6      2 · 3 ··· 10 · 11
                  691 n (n − 1) ··· (n − 10) ω 11  n−11
                −     ·                      x
                  210       2 · 3 ··· 12 · 13
                  35 n (n − 1) ··· (n − 12) ω 13  n−13
                +    ·                      x
                   2       2 · 3 ··· 14 · 15
                                            15
                  3617 n (n − 1) ··· (n − 14) ω  n−15
                −      ·                      x
                   30        2 · 3 ··· 16 · 17
                  43867 n (n − 1) ··· (n − 16) ω 17  n−17
                +       ·                      x
                    42        2 · 3 ··· 18 · 19
                  1222277 n (n − 1) ··· (n − 18) ω 19  n−19
                −         ·                      x
                    110         2 · 3 ··· 20 · 21
                                              21
                  854513 n (n − 1) ··· (n − 20) ω  n−21
                +        ·                      x
                     6         2 · 3 ··· 22 · 23
                  1181820455 n (n − 1) ··· (n − 22) ω 23  n−23
                −            ·                      x
                      546          2 · 3 ··· 24 · 25
                  76977927 n (n − 1) ··· (n − 24) ω 25  n−25
                +          ·                      x
                      2          2 · 3 ··· 26 · 27
                                                   27
                  23749461029 n (n − 1) ··· (n − 26) ω  n−27
                −             ·                      x
                       30           2 · 3 ··· 28 · 29
                  8615841276005 n (n − 1) ··· (n − 28) ω 29  n−29
                +               ·                      x
                       462            2 · 3 ··· 30 · 31
                + ··· + C.



        The main interest here is the sequence of purely numerical coefficients. It
        is not yet time to explain how these are formed.
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