Alternating Series

Question

Test the series for convergence or divergence, I already solved all of it except the last part

∑(n=1, infinity) ((-1)^n)/((n)(2^n))

b_n=1/(n2^n)

lim as n approaches infinity b_n= 0; The series is convergent

If the series is convergent, use the Alternating Series Estimation Theorem to determine how many terms we need to add in order to find the sum with an error less than 0.0001? (If the quantity diverges, enter DIVERGES.) How many terms?

Answer 1

Last quetion>

1/[n2ⁿ) < 0.0001;

It started from n = 10. So, n ≥ 10.