\(\mathop {\lim }\limits_{x \to - 2} \dfrac{{4{x^3} - 1}}{{3{x^2} + x + 2}}\) bằng

Câu hỏi :

\(\mathop {\lim }\limits_{x \to  - 2} \dfrac{{4{x^3} - 1}}{{3{x^2} + x + 2}}\) bằng

A. \( - \infty \)

B. \(\dfrac{{ - 11}}{4}\)

C. \(\dfrac{{11}}{4}\)

D. \( + \infty \)

* Đáp án

B

* Hướng dẫn giải

\(\mathop {\lim }\limits_{x \to  - 2} \dfrac{{4{x^3} - 1}}{{3{x^2} + x + 2}} \) \(= \dfrac{{4.{{( - 2)}^2} - 1}}{{3.{{( - 2)}^2} + ( - 2) + 2}} = \dfrac{{ - 33}}{{12}} = \dfrac{{ - 11}}{4}\)

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