We prove a new sharpening of the inequality A detailed proof of (2) as well as many related results can be found in [3].
A refinement of Vietoris' inequality for sine polynomials
โ Scribed by Horst Alzer; Stamatis Koumandos; Martin Lamprecht
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 90 KB
- Volume
- 283
- Category
- Article
- ISSN
- 0025-584X
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
Let
equation image
where
equation image
In 1958, Vietoris proved that ฯ~n~ (x) is positive for all n โฅ 1 and x โ (0, ฯ). We establish the following refinement. The inequalities
equation image
hold for all natural numbers n and real numbers n โฅ 1 and x โ (0, ฯ) if and only if
equation image
๐ SIMILAR VOLUMES
In this paper, we obtain an improved discrete Wirtinger inequality associated with a nonlinear second order differential equation. We apply this result to prove a Bonnesen-style isoperimetric inequality for plane polygons and reinterpret the main theorem as a weighted exponential inequality.
Let p n z be a polynomial of degree n and D ฮฑ p n z its polar derivative. It has been proved that if p n z has no zeros in z < 1, then for ฮด โฅ 1 and ฮฑ โฅ 1, 2ฯ 0 D ฮฑ p n e iฮธ ฮด dฮธ 1/ฮด โค n ฮฑ + 1 F ฮด 2ฯ 0 p n e iฮธ ฮด dฮธ 1/ฮด where F ฮด = 2ฯ/ 2ฯ 0 1 + e iฮธ ฮด dฮธ 1/ฮด . We also obtain analogous inequalities