Exact enclosures of roots of interval quadratic equations by Sridhara's and Fagnano's or modified Fagnano's formulas

I. Elishakoff and A. Daphnis

Applied Mathematics and Computation, 2015, vol. 271, issue C, 1024-1037

Abstract: In this study we investigate the question of accurate determination of the root enclosures of quadratic equations whose coefficients constitute interval variables. We treat several special cases where either Sridhara's classical formula or Fagnano's alternative expression provide exact interval enclosures for the roots of the quadratic equation. In the case of a single coefficient serving as an interval, it is shown that the classical interval analysis by either Sridhara's, Fagnano's or specifically modified Fagnano's formulas provide lower and upper bounds of roots. Then we follow with the case of two coefficients being intervals whereas the third coefficient is a deterministic quantity. Numerous examples are provided in which the solutions are compared with the direct numerical evaluation of the roots' enclosures. In three arising cases either Sridhara's or Fagnano's expressions suffice to obtain exact enclosures.

Keywords: Sridhara's quadratic equation; Fangano's quadratic equation; Interval analysis (search for similar items in EconPapers)
Date: 2015
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0096300315012230
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:apmaco:v:271:y:2015:i:c:p:1024-1037

DOI: 10.1016/j.amc.2015.09.005

Access Statistics for this article

Applied Mathematics and Computation is currently edited by Theodore Simos

More articles in Applied Mathematics and Computation from Elsevier
Bibliographic data for series maintained by Catherine Liu ().