Giá trị của giới hạn \[\mathop {\lim }\limits_{x \to - \infty } \left( {x - {x^3} + 1} \right)\] là:

A.\[\mathop {\lim }\limits_{x \to {x_0}} \left[ {f\left( x \right) + g\left( x \right)} \right] = L\]

B. \[\mathop {\lim }\limits_{x \to {x_0}} \left[ {f\left( x \right) + g\left( x \right)} \right] = M\]

C. \[\mathop {\lim }\limits_{x \to {x_0}} \left[ {f\left( x \right) + g\left( x \right)} \right] = L - M\]

D. \[\mathop {\lim }\limits_{x \to {x_0}} \left[ {f\left( x \right) + g\left( x \right)} \right] = M + L\]

A.0.

B.1.

C.2.

D.3.

A.\[ + \infty .\]

B.2.

C.4.

D.\[ - \infty .\]

A.\[T = \frac{{12}}{{25}}.\]

B. \[T = \frac{4}{{25}}.\]

C. \[T = \frac{4}{{15}}.\]

D. \[T = \frac{6}{{25}}.\]

A.\[\mathop {\lim }\limits_{x \to + \infty } {x^n} = - \infty \]

B. \[\mathop {\lim }\limits_{x \to \pm \infty } {x^n} = + \infty \]

C. \[\mathop {\lim }\limits_{x \to - \infty } {x^n} = - \infty \]

D. \[\mathop {\lim }\limits_{x \to - \infty } {x^n} = + \infty \]

A.\[\frac{1}{5}.\]

B. \[\sqrt 5 .\]

C. \[\frac{1}{{\sqrt 5 }}.\]

D. 5

A.\[\mathop {\lim }\limits_{x \to + \infty } \frac{{{x^2} + 1}}{{2{x^2} + 1}} = \frac{1}{2}\]

B. \[\mathop {\lim }\limits_{x \to - \infty } \left( {{x^2} + 3x - 1} \right) = - \infty \]

C. \[\mathop {\lim }\limits_{x \to + \infty } \frac{{x + 1}}{{2x + 1}} = \frac{1}{2}\]

D. \[\mathop {\lim }\limits_{x \to - \infty } \frac{{x + 3}}{{2x + 1}} = \frac{1}{2}\]