thank you so much for your help! I have a final today and this type of problem confuses me so much. I couldn't figure it out, but I at least got a little closer to the answer. I made the correction you pointed out about the negative sign. Then I was able to use your hint to get the series to...
Homework Statement
Find the power series representation of f(x)= 1/((4+x)^2).
Use this representation to determine the sum of the series:
sum [1, infinity) of n*(3/8)^n.
I attached a screenshot of the problem for just in case.
Homework Equations
The Attempt at a Solution
What I...