Question

If you have a series: sigma starting from n=3 to infinity of [(n-2)/2^(n-1)] * (-2)^n, how do you test if it is convergent or divergent?
to me it looks alternating so i tried AST but i dont think it works. How does the process go when applying the test for divergence in this case?
I get stuck in the following step: lim as n goes to infinity of (2n-4)/(-1)^n where I try to use L'Hospital rule but get nowhere after that.

Answer 1

use the divergence test