Tìm giới hạn \(B=\lim\limits _{x \rightarrow-\infty}\left(x-\sqrt{x^{2}+x+1}\right)\)

* Hướng dẫn giải

\(B=\lim \limits_{x \rightarrow-\infty}\left(x-|x| \sqrt{1+\frac{1}{x}+\frac{1}{x^{2}}}\right)=\lim\limits _{x \rightarrow-\infty} x\left(1+\sqrt{1+\frac{1}{x}+\frac{1}{x^{2}}}\right)=-\infty\)