I need help determining if these alternating series converge absolutely, converge conditionally or diverge. Give reasons.

a) the sum (from n=1 to infinity) of (-1)^n [tanh n / n ]

note tanh n>0 for all n>0

b) the sum (from n=1 to infinity) of (-1)^n [sinh(n / 8n+1)]

note: sinh n > 0 for all n > 0

Any help with these problems is greatly appreciated!

K