Interval of Convergence Checking for Endpoints?

Question

For (-1^n+1 * x^n) / 4n
- I got (-4,4) for my endpoints
-plug in 4 I get -1, how would I deter converge or diverge from that -1?
- plug in -4 and get 1 , how would I deter. converge or diverge from that 1?

(x-3)^(n-1) / 3^(n-1)
- got (0,6) as endpoints
- plug in 6 i get 1, how would I deter converge or diverge?
- plug in 0 and get -1, " " " " " " " "" ?

Answer 1

It's pretty simple really.
Any series will diverge if the terms do not converge to 0. So if the terms are always 1 or -1, it diverges.