Find the radius of convergence for ∑n=1∞xnnn\sum_{n=1}^{\infty} \frac{x^n}{n^n}∑n=1∞nnxn using the root test.
R=0R = 0R=0
R=1R = 1R=1
R=eR = eR=e
R=∞R = \inftyR=∞