Cho hàm số \(f\left( x \rig...

C

- Hướng dẫn giải

\(\mathop {\lim }\limits_{x \to + \infty } f\left( x \right) = + \infty \Rightarrow a > 0.\)

\(f\left( 0 \right) = - 1 \Rightarrow d = - 1 < 0.\)

\(f'\left( x \right) = 3a{x^2} + 2bx + c.\)

\(\left\{ \begin{array}{l}{x_1} + {x_2} = - 2\\{x_1}{x_2} = 0\end{array} \right. \Rightarrow \left\{ \begin{array}{l} - \frac{{2b}}{{3a}} = - 2\\\frac{c}{{3a}} = 0\end{array} \right. \Rightarrow \left\{ \begin{array}{l}b = 3a > 0\\c = 0\end{array} \right..\)