1. The problem statement, all variables and given/known data Ʃ(-1/2)^k from 0 to infinity. 2. Relevant equations Ʃ(-1)^k*B_n from 0 to infinity where if the series converges 1. lim of B_n as n goes to infinity must = 0 2. B_n must be decreasing 3. The attempt at a solution It doesn't look like there is a B_n in the original equation at all. Do I manipulate it algebraically somehow to extract the B_n, or is there some clever trick? Is the B_n simply 1? If if that's the case, lim of 1 as n goes to infinity would just be one, but apparently that's not true from checking the answer (which is it does, indeed, converge). Thanks.