Question

tìm \(lim\left[\sqrt{n+1}\left(\sqrt{n+3}-\sqrt{n+2}\right)\right]\)

Answer 1

\(\lim[\sqrt{n+1}(\sqrt{n+3}-\sqrt{n+2})] =\lim[\sqrt{n+1}(\dfrac{n+3-n-2}{\sqrt{n+3}+\sqrt{n+2}})] =\lim[\sqrt{n}.\sqrt{1+\dfrac{1}{n}}.\dfrac{1}{\sqrt{n}.\sqrt{1+\dfrac{3}{n}}+\sqrt{n}.\sqrt{1+\dfrac{2}{n}}}] =\dfrac{1}{2}\)