Given the convergence criteria the sum should be 3 - (1/[1+1/3]) = 3 - 3/4 = 12/4 - 3/4 = 9/4
I have numerically verified that the following sum comes to , the same thing the back of the book says. So what'd I do wrong?
Find the sum of the convergent series
I verified that the above sum can be represented as
which can be rewritten as
I believe I can apply the geometric series to the summation, giving me
Ahhh... but now I see that the geometric series equation starts the summation at (do you find that typing up your answers sometimes helps you realize what's wrong? Why is that?).
So, I need to subtract from my answer, which (unsurprisingly) gives .