b.
\(\lim\limits_{x\rightarrow-\infty}\left(\sqrt{x^2+3x-1}+x\right)=\lim\limits_{x\rightarrow-\infty}\left(\dfrac{3x-1}{\sqrt{x^2+3x-1}-x}\right)\)
\(=\lim\limits_{x\rightarrow-\infty}\left(\dfrac{3-\dfrac{1}{x}}{-\sqrt{1+\dfrac{3}{x}-\dfrac{1}{x^2}}-1}\right)=\dfrac{3-0}{-1-1}=-\dfrac{3}{2}\)
d.
\(\lim\limits_{x\rightarrow-\infty}\dfrac{2x^2+3x}{\sqrt{4x^4+2x^2}+3x^2-1}=\lim\limits_{x\rightarrow-\infty}\dfrac{2+\dfrac{3}{x}}{\sqrt{4+\dfrac{2}{x^2}}+3-\dfrac{1}{x^2}}\)
\(=\dfrac{2+0}{\sqrt{4+0}+3-0}=\dfrac{2}{5}\)
Đúng 1
Bình luận (0)
