Im having trouble with this power series, I know it converges absolutely but im having trouble getting there.
any help appreciated, Thanks.
If this power series isn't known to you (which it really should be) we can find it slighly differently. Suppose we just want to find the explicity function described by notice that we may (take for granted here that you can...there is criterion it needs to meet but it does...so) differentate to obtain . Therefore, . And seeing that we can conclude that therefore .