Bài tập 5.115 trang 217 SBT Toán 11

A. \(df(x) = {{ - \sin 4x} \over {2\sqrt {1 + {{\cos }^2}2x} }}dx\)

B. \(df(x) = {{ - \sin 4x} \over {\sqrt {1 + {{\cos }^2}2x} }}dx\)

C. \(df(x) = {{\cos 2x} \over {\sqrt {1 + {{\cos }^2}2x} }}dx\)

D. \(df(x) = {{ - \sin 2x} \over {2\sqrt {1 + {{\cos }^2}2x} }}dx\)

A. \({{ - x} \over {2\sin {x^2}}}\)

B. \({x \over {{{\sin }^2}{x^2}}}\) 

C. \({{ - x} \over {\sin {x^2}}}\)

D. \({{ - x} \over {{{\sin }^2}{x^2}}}\)

A. \(y'\left( {{\pi  \over 6}} \right) = 1\)

B. \(y'\left( {{\pi  \over 6}} \right) =  - 1\)

C. \(y'\left( {{\pi  \over 6}} \right) = 2\)

D. \(y'\left( {{\pi  \over 6}} \right) =  - 2\)

A. \(\left( { - \infty ;0} \right]\)

B. \(\left( { - \infty ;0} \right)\)

C. \((0; + \infty )\)

D. \(\emptyset \)

A. \(\left\{ 0 \right\}\)   

B. \(\mathbb{R}\)

C. \(\mathbb R\backslash \left\{ 0 \right\}\) 

D. \(\emptyset \)  

A. \({{x - 6{x^2}} \over {\sqrt {{x^2} - 4{x^3}} }}\)

B. \({1 \over {2\sqrt {{x^2} - 4{x^3}} }}\)

C. \({{x - 12{x^2}} \over {2\sqrt {{x^2} - 4{x^3}} }}\)

D. \({{x - 6{x^2}} \over {2\sqrt {{x^2} - 4{x^3}} }}\)

A. \({2 \over {{{(x + 1)}^2}}}\)

B. \({3 \over {{{(x + 1)}^2}}}\)   

C. \({1 \over {{{(x + 1)}^2}}}\)

D. \({{ - 1} \over {{{(x + 1)}^2}}}\)