Question

so sánh các biểu thưcs sau

a)\(\sqrt[3]{9}\)và 2

b)\(2\sqrt[3]{3}\)và\(3\sqrt[3]{2}\)

c)\(\sqrt{2}+1\)và\(\sqrt[3]{7+5\sqrt{2}}\)

Answer 1

a: \(\sqrt[3]{9}>\sqrt[3]{8}=2\)

b: \(2\sqrt[3]{3}=\sqrt[3]{24}< \sqrt[3]{54}=3\sqrt[3]{2}\)

c: \(\sqrt{2}+1=\sqrt[3]{7+5\sqrt{2}}\)

Answer 2

\(\text{a},2=\sqrt[3]{8}\)

ma 8 <9

=> \(\sqrt[3]{9}>\sqrt[3]{8}=>\sqrt[3]{9}>2\)

\(b,\sqrt[3]{8.3}=\sqrt[3]{24};\sqrt[3]{27.2}=\sqrt[3]{54}=>\sqrt[3]{24}< \sqrt[3]{54}=>2\sqrt[3]{3}< 3\sqrt[3]{2}\)

\(\sqrt[3]{7+5\sqrt{2}}=^3\sqrt{\left(\sqrt{2}+1\right)^3}=\sqrt{2}+1\)