[tex]a_n= n^{-3}+n^{-1}=\dfrac{1}{n^3}+\dfrac{1}{n}\\\\\displaystyle \limit\lim_{n\to \infty} a_n=\limit\lim_{n\to\infty}\left(\dfrac{1}{n^3}+\dfrac{1}{n} \right)=0 [/tex]
