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## Discussion of Problem 1503. Polynomial

Question
Posted by svr 31 Oct 2006 00:22
Number of solutions depend on untold rounding rules.
For exaple, let our algorithm gave comlex root
1+0.0000001*i. What descision, include 1 to real roots or not. For me right answer may vary in root numbers but contain in it's 0.000001 - neighbornhood ideal mathamatical set of roots.
Re: Question
Posted by svr 31 Oct 2006 14:07
It seems that with type double and 16 righs digits in results the problem impossible to solve. For examle if we try compair solutions x1=0.999988 and x2=0.999982 for equation f(x)=(x-1)^4=x^4-4*x^3+6*x^2-4*x+1=0 computer
says that x2 is better. If we have 30-digits floats we would correct answer by optimization near initial approximation. If somebody knows internet resources with such module I shall be grateful.