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RealRootRefine

refine a real root of a univariate polynomial

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

Description
This function computes a refinement of a real root of a univariate polynomial over QQ 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 := [-1, 0, 2], inf := -3/2, sup := -5/4]

/**/  RR := [RealRootRefine(Root, 10^(-20)) | Root In RR];
/**/  FloatStr(RR[1].inf);
-1.414213562*10^0

See Also