1. The problem statement, all variables and given/known data Find a closed form expression for the function f(x) which the power series Σn=0..∞ n(-1)nxn+1 converges to and determine the values of x for which f(x) equals the given power series. 2. Relevant equations N/A 3. The attempt at a solution I'm actually not sure how to start. First, what does it mean by "closed form expression"? Does that just mean an expression that isn't expressed as a series (with summation notation)? The only thing I can think of is writing the terms out. That's probably not right though. If anyone can give me a hint or nudge me in the right direction, I'd be extremely grateful. Thank you.