Use the Ratio test to determine whether the series converges or diverge ∞ ∑       (-1)n(2n+1)/n! n=1

Use ratio test to determine if the series is absolutely convergent or not.

#5 I think its 12 and convergent. i think you're suppose to use correlation to geometric series

Use the Ratio Test to determine the convergence or divergence of the series. If the Ratio Test is inconclusive, determine the convergence or divergence of the series using other methods. (If you need to use o or -00, enter INFINITY or -INFINITY, respectively.) * (2n)! n = 1 a n + 1 lim %3D n → 00 an converges diverges