consider the series:

n=1 infinity

(-1)^n/( sqrt(n) +1) or

n=1 infinity

(-1)^n/(n!)^2

I understand that these series satisfy the alternating series test.

How many terms need to be added in order to reach within 10^-8 of the sum of the series?

I also need to figure out how to give a decimal approximation of the sum of one of these series with the maximum allowed error of 10^-8.

Thank you!