CoCoA:RealRootsApprox

RealRootsApprox

computes approximations to the real roots of a univariate polynomial

Description

This function computes rational approximations to the real roots of a

univariate polyomial (with rational coefficients).

An optional second argument specifies the maximum separation between

the approximations produced and the corresponding exact root. An

optional third argument specifies a closed interval in which to search for roots.

Example

  RealRootsApprox(x^2-2);
[-3037000499/2147483648, 3037000499/2147483648]
-------------------------------
  RR := RealRootsApprox(x^2-2, 10^(-15), [0, 2]);
  RR;
[6521908912666391107/4611686018427387904]
-------------------------------
  FloatStr(RR[1], 15);
1.41421356237310*10^0
-------------------------------

Syntax

RealRootsApprox(F:POLY):LIST
RealRootsApprox(F:POLY, Precision:RAT):LIST
RealRootsApprox(F:POLY, Precision:RAT, Interval:[RAT,RAT]):LIST

RealRoots

RootBound

   <type>polynomial</type>