1)
lim \frac{(1-\sqrt{x})(1-\sqrt[3]{x})...(1-\sqrt[n]{x})}{(1-x)^{n-1}} KQ:
\frac{1}{n!}
2)\mathop {\lim }\limits_{x \to 0} \frac{(\sqrt{1+x^{2}}+x)^{2009} - (\sqrt{1+x^{2}}-x)^{2009}}{x} KQ: 4018
3) \mathop {\lim }\limits_{x \to 1} (\frac{2011}{1-x^{2011}}-\frac{2012}{1-x^{2012}}) KQ: \frac{-1}{2}
4)\mathop {\lim }\limits_{x \to 1} \frac{x^{2}-4}{\cos \frac{\pi x}{4}} KQ: \frac{-16}{\pi }
5)\mathop {\lim }\limits_{x \to 1} [(1+x)(1+x^{2})(1+x^{4}...(1+x^{2})] với \left| {x} \right| <1 KQ: \frac{1}{1-x}