\(\mathop {\lim }\limits_{x \to - \infty } ({x^3} + {x^2} + 1)\) bằng
A. 1
B. \(+ \infty\)
C. \(- \infty\)
D. - 1
\(\mathop {\lim }\limits_{x \to - \infty } \left( {{x^3} + {x^2} + 1} \right) = \mathop {\lim }\limits_{x \to - \infty } {x^3}\left( {1 + \frac{1}{x} + \frac{1}{{{x^3}}}} \right) = - \infty \)
Chọn C.
-- Mod Toán 11