$($If it diverges to infinity, state your answer as inf. If it diverges to negative infinity, state your answer as $-$inf. If it diverges without being infinity or negative infinity, state your answer as DNE$)$

$\underset{n}{lim}(-1{)}^{n}sin(\frac{11}{n})=$

$\underset{n}{lim}\frac{ncos(n)}{2n-1}=$