Hàm số \(y = \frac{1}{{{x^2} - 3x + 2}}\) liên tục trên khoảng nào dưới đây? 

\(\mathop {\lim }\limits_{n \to + \infty } \frac{{\left( {a - 1} \right)n + 2}}{{2n + 9}} = 1\)\( \Leftrightarrow \mathop {\lim }\limits_{n \to + \infty } \frac{{\left( {a - 1} \right) + \frac{2}{n}}}{{2 + \frac{9}{n}}} = 1\)\( \Leftrightarrow \frac{{a - 1}}{2} = 1\)\( \Leftrightarrow a = 3\).

\(\mathop {\lim }\limits_{x \to - \infty } \frac{{\sqrt {4{x^2} - x + 11} }}{{x + 2025}}\)\( = \mathop {\lim }\limits_{x \to - \infty } \frac{{ - x\sqrt {4 - \frac{1}{x} + \frac{{11}}{{{x^2}}}} }}{{x\left( {1 + \frac{{2025}}{x}} \right)}}\)\( = \mathop {\lim }\limits_{x \to - \infty } \frac{{ - \sqrt {4 - \frac{1}{x} + \frac{{11}}{{{x^2}}}} }}{{\left( {1 + \frac{{2025}}{x}} \right)}}\) = −2.

Trả lời: −2.