Tính các giới hạn sau: a) \(\mathop {\lim }\limits_{x \to - \infty } \frac\); b) \(\mathop {\lim }\limits_{x \to + \infty } \frac\); c) \(\mathop {\lim }\limits_{x \to - \infty } \frac{{\sqrt {9{x^2} - x + 1} }}\); d) \(\mathop {\lim }\limits_{x \to + \infty } \frac{{\sqrt {9{x^2} - x + 1} }}\); e) \(\mathop {\lim }\limits_{x \to - {2^ - }} \frac{{3{x^2} + 4}}\); g) \(\mathop {\lim }\limits_{x \to - {2^ + }} \frac{{3{x^2} + ...

Tính các giới hạn sau:

a) \(\mathop {\lim }\limits_{x \to - \infty } \frac\);

b) \(\mathop {\lim }\limits_{x \to + \infty } \frac\);

c) \(\mathop {\lim }\limits_{x \to - \infty } \frac{{\sqrt {9{x^2} - x + 1} }}\);

d) \(\mathop {\lim }\limits_{x \to + \infty } \frac{{\sqrt {9{x^2} - x + 1} }}\);

e) \(\mathop {\lim }\limits_{x \to - {2^ - }} \frac{{3{x^2} + 4}}\);

g) \(\mathop {\lim }\limits_{x \to - {2^ + }} \frac{{3{x^2} + 4}}\).