Cho \[f = {R^3} \to {R^3}\],  Tập V tất cả \[\left( {{x_1},{x_2},{x_3}} \right)f\left( {{x_1},{x_2},{x_3}} \right) = \left( {{x_1} + {x_2} + {x_3},{x_1} + {x_2} + {x_3},{x_1} - {x_2} - {x_3}} \right)\] thỏa \[f\left( {{x_1},{x_2},{x_3}} \right) = 0\] là:

A. \[I = \frac{{4({x^2} + 5)}}{{7\sqrt[4]{x}}} + C\]

B. \[I = \frac{{3({x^2} + 7)}}{{7\sqrt[3]{x}}} + C\]

C. \[I = \frac{{3({x^2} + 7)}}{{7\sqrt[4]{x}}} + C\]

D. \[I = \frac{{4({x^2} + 7)}}{{7\sqrt[4]{x}}} + C\]

A. \[A = \left( {\begin{array}{*{20}{c}}\begin{array}{l}1\\ - 2\\ - 1\end{array}&\begin{array}{l} - 2\\0\\0\end{array}&\begin{array}{l} - 1\\0\\0\end{array}\end{array}} \right)\]

B. \[A = \left( {\begin{array}{*{20}{c}}\begin{array}{l}1\\ - 1\\\frac{{ - 1}}{2}\end{array}&\begin{array}{l} - 1\\0\\0\end{array}&\begin{array}{l}\frac{{ - 1}}{2}\\0\\0\end{array}\end{array}} \right)\]

C. \[A = \left( {\begin{array}{*{20}{c}}\begin{array}{l}\frac{1}{2}\\ - 1\\\frac{{ - 1}}{2}\end{array}&\begin{array}{l} - 1\\0\\0\end{array}&\begin{array}{l}\frac{{ - 1}}{2}\\0\\0\end{array}\end{array}} \right)\]

A. \[ - \cot \frac{x}{2}\]

B. \[\cot \frac{x}{2}\]

C. \[ - \frac{1}{2}\cot g\frac{x}{2}\]

D. \[ - 2\cot g\frac{x}{2}\]

A. m > 2

B. m≤2

C. m = 2

D. ∀m∈R

A. \[I = \frac{1}{2}{e^{2x}} - {e^x} + x + C\]

B. \[I = \frac{1}{2}{e^{2x}} - {e^{ - x}} + x + C\]

C. \[I = \frac{1}{2}{e^{3x}} - {e^{ - x}} + x + C\]

D. \[I = \frac{1}{2}{e^{2x}} + {e^{ - x}} + x + C\]

A. m > 25

B. m≤25

C. m = 25

D. Không có giá trị m

A. 1

B. 2

C. -2

D. -3