គេឲ្យ $a_{1}=1$ , $a_{n+1}=a_n+3n^2+3n+1$ ។ ចូរគណនា $a_n$
ចូរគណនាលីមីត
ក. $\displaystyle \lim_{x \to \infty}{\dfrac{1^k+2^k+\dots+n^k}{n^{k+1}}}$
ខ. $\displaystyle \lim_{x \to \infty}{(\dfrac{n}{n^2+1}+\dfrac{n}{n^2+4}+\dots+\dfrac{n}{n^2+n^2})}$
គ. $\displaystyle \lim_{x \to \infty}{(\dfrac{n}{n+1}+\dfrac{n}{n+2}+\dots+\dfrac{n}{n+n})}$
ឃ. $\displaystyle \lim_{x \to \infty}{\sum_{k=1}^{ n}{\ln (1-\dfrac{k}{k+n})^{\dfrac{1}{n}}}}$
ក. $\displaystyle \lim_{x \to \infty}{\dfrac{1^k+2^k+\dots+n^k}{n^{k+1}}}$
ខ. $\displaystyle \lim_{x \to \infty}{(\dfrac{n}{n^2+1}+\dfrac{n}{n^2+4}+\dots+\dfrac{n}{n^2+n^2})}$
គ. $\displaystyle \lim_{x \to \infty}{(\dfrac{n}{n+1}+\dfrac{n}{n+2}+\dots+\dfrac{n}{n+n})}$
ឃ. $\displaystyle \lim_{x \to \infty}{\sum_{k=1}^{ n}{\ln (1-\dfrac{k}{k+n})^{\dfrac{1}{n}}}}$