2.10.127 Number Series

Condition: Explore the convergence of the numerical row: a) \ (\ sum_ {n = 0}^{\ infty} \ frac {3^{n}} {(2 n)!} \) B) \ (\ sum_ {n = 0} {\ Infty} \ frac {(-1)^{n}} {(2 n+1)^{2}} \).