Use the ratio test to determine whether sum_{n=22}^{infinity} 9^n / (2n)! converges or diverges.
(a) Find the ratio of successive terms. Write your answer as a fully simplified fraction. For n >= 22,
lim_{n->infinity} |a_{n+1} / a_n| = lim_{n->infinity}
(b) Evaluate the limit in the previous part. Enter infinity as infinity and -infinity as -infinity. If the limit does not exist, enter DNE.
lim_{n->infinity} |a_{n+1} / a_n| =
(c) By the ratio test, does the series converge, diverge, or is the test inconclusive? Choose