# Math Help - null sequences - help.....

1. ## null sequences - help.....

{an} = { (-1)^n }
{ n^2 }

Show this is a null sequence. Can anybody help.?.?.?

2. Originally Posted by Craige
Let $\epsilon > 0$ and choose $N=\frac{1}{\sqrt{\epsilon}}$.
Then if $n>N$ it will follow that $|a_n|<\epsilon$.