TQ : limx→1√x.3√x.4√x...n√x−1x−1=12+...+1nTự áp dụng :v
TQ : $\mathop {\lim }\limits_{x \to 1}\frac{\sqrt{x}.\sqrt[3]{x}.\sqrt[4]{x}...\sqrt[n]{x}-1}{x-1}=\mathop {\lim }\limits_{x \to 1}\frac{(\sqrt[n]{x}-1)\sqrt[n-1]{x}...\sqrt{x}+...+(\sqrt{x}-1)}{x-1}=\mathop {\lim }\limits_{x \to 1}\frac{1}{\sqrt{x}+1}+...+\frac{1}{\sqrt[n-1]{x}+...+1}=\frac{1}{2}+...+\frac{1}{n}$Tự áp dụng :v