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RealRootRefine

Syntax

RealRootRefine(Root:RECORD, Precision:RAT):RECORD
    

Summary

refine a root of a univariate polynomial over Q

Description

This functions computes a refinement of a real root of a univariate polynomial over Q to the desired precision (width of isolating interval). The starting root must be a record produced by RealRoots.

example

    
RR := RealRoots(x^2-2);
RealRootRefine(RR[1], 1/2);
Record[ CoeffList = [-8, 1456, -712], Inf = -91/64, Sup = -45/32]
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RR := [RealRootRefine(Root, 10^(-20)) | Root In RR];
FloatStr(RR[1].Inf);
-1.414213562*10^0
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See Also