So if:formula_18 is our polynomial; and:formula_19 are the roots we have found, then consider the product:formula_20By the المبرهنة الأساسية في الجبر, "R"("x") should be equal to "P"("x"), if all the roots of "P"("x") are rational.
So if:formula_18 is our polynomial; and:formula_19 are the roots we have found, then consider the product:formula_20By the fundamental theorem of algebra, "R"("x") should be equal to "P"("x"), if all the roots of "P"("x") are rational.