Okay perhaps the title isn't specific enough, I didn't know how to word it exactly. I'm finding the interval of convergence for a power series and i know the answer to be (-2,0]
I end up with the inequality $|x+1|<-1$, my question is how do I resolve the interval (-2,0] from that, I'm sure the answer is probably easier than I'm making it out to be?
Would I make it: $-1<x+1<1$ and than subtract 1 from both sides? If yes, how come I could put negative 1 on the side which makes it less than $x+1$, when previously it was greater?