- Tytuł:
- On some quadrature rules with Gregory end corrections
- Autorzy:
-
Bożek, B.
Solak, W.
Szydełko, Z. - Powiązania:
- https://bibliotekanauki.pl/articles/255170.pdf
- Data publikacji:
- 2009
- Wydawca:
- Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
- Tematy:
-
numerical integration
quadrature formulas
summation of series - Opis:
- How can one compute the sum of an infinite series s := a1 + a2 + ź ź ź ? If the series converges fast, i.e., if the term a(n) tends to 0 fast, then we can use the known bounds on this convergence to estimate the desired sum by a finite sum a1 +a2 +ź ź ź+a(n). However, the series often converges slowly. This is the case, e.g., for the series a(n) = n(-t) that defines the Riemann zeta-function. In such cases, to compute s with a reasonable accuracy, we need unrealistically large values n, and thus, a large amount of computation. Usually, the n-th term of the series can be obtained by applying a smooth function ƒ(x) to the value n: an = ƒ(n). In such situations, we can get more accurate estimates if instead of using the upper bounds on the remainder infinite sum R = ƒ(n + 1) + ƒ(n + 2) + . . ., we approximate this remainder by the corresponding integral I of ƒ(x) (from x = n + 1 to infinity), and find good bounds on the difference I - R. First, we derive sixth order quadrature formulas for functions whose 6th derivative is either always positive or always negative and then we use these quadrature formulas to get good bounds on I - R, and thus good approximations for the sum s of the infinite series. Several examples (including the Riemann zeta-function) show the efficiency of this new method. This paper continues the results from [3] and [2].
- Źródło:
-
Opuscula Mathematica; 2009, 29, 2; 117-129
1232-9274
2300-6919 - Pojawia się w:
- Opuscula Mathematica
- Dostawca treści:
- Biblioteka Nauki
Artykuł