\(lim\left(\sqrt{9n^2+10n}-an\right)=-\infty\)
\(\Leftrightarrow lim\dfrac{9n^2+10n-a^2n^2}{\sqrt{9n^2+10n}}=-\infty\)
\(\Leftrightarrow lim\dfrac{9-a^2+\dfrac{10}{n}}{\sqrt{\dfrac{9}{n^2}+\dfrac{10}{n^3}}}=-\infty\)
\(\Leftrightarrow\dfrac{9-a^2}{0}=-\infty\)
\(\Rightarrow a^2>9\)
\(\Leftrightarrow a>3\) \(\Rightarrow a\in\left[4;2023\right]\)