Question

Tìm nghiệm của đa thức:

-10x³ + 7x + 13 = 0

Answer 1

-10x³ + 7x + 13 = 0

\(\Leftrightarrow x=\frac{\left(39\sqrt{15}+148,758193051677\right)^{\frac{1}{3}}}{\sqrt[3]{4}\sqrt{15}}+\frac{7\sqrt[3]{4}}{2\sqrt{15}\left(39\sqrt{15+148,758193051677}\right)^{\frac{1}{3}}}\)

\(\Leftrightarrow x=-\frac{\left(\sqrt{22129}+13\sqrt{27}\sqrt{5}\right)^{\frac{2}{3}}\left(\sqrt{3}i+1\right)-7\sqrt[3]{2}\sqrt{3}i+7\sqrt[3]{2}}{\sqrt[3]{32}\sqrt{3}\sqrt{5}\left(\sqrt{22129}+13\sqrt{27}\sqrt{5}\right)^{\frac{1}{3}}}\)

\(\Leftrightarrow x=\frac{\left(\sqrt{22129}+13\sqrt{27}\sqrt{5}\right)^{\frac{2}{3}}\left(\sqrt{3}i-1\right)-7\sqrt[3]{2}\sqrt{3}i-7\sqrt[3]{2}}{\sqrt[3]{32}\sqrt{3}\sqrt{5}\left(\sqrt{22129}+13\sqrt{27}\sqrt{5}\right)^{\frac{1}{3}}}\)