so sánh

tan 52 và cos 58

cotan 42 và cos 42

\(\dfrac{a}{\sqrt{a^2-b^2}}-\left(1+\dfrac{a}{\sqrt{a^2-b^2}}\right):\dfrac{b}{a-\sqrt{a^2-b^2}}\)

\(x^2-3x\sqrt{y}+2y\) với x=\(\dfrac{1}{\sqrt{5}-2}\) và y=\(\dfrac{1}{9+4\sqrt{5}}\)

\(\sqrt{\dfrac{5+2\sqrt{6}}{5-\sqrt{6}}}+\sqrt{\dfrac{5-2\sqrt{6}}{5+\sqrt{6}}}\)

\(\sqrt[3]{5\sqrt{2}+7}-\sqrt[3]{5\sqrt{2}-7}\)

Mark the letter A, B, C or D on your answer sheet to indicate the word (s) CLOSEST in meaning to the underlined word (s) in each of the following questions

Today, American English is particularly influential, due to the USA’s dominance of cinema, television, popular music, trade and technology (including the Internet)

A. complete mastery

B.overwhelming superiority 

C. complete control 

D. profound effect