Homework Statement
Consider the power series.
sigma (n=1 to infinity) x^n / [n(n+1)]
if f(x) = sigma x^n / [n(n+1)], then compute a closed-form expression for f(x).
It says: "Hint: let g(x) = x * f(x) and compute g''(x). Integrate this twice to get back to g(x) and hence derive...