Given ∑n=1∞an\sum_{n=1}^{\infty} a_n∑n=1∞an converges, which of the following must be true?
limn→∞an=1\lim_{n \to \infty} a_n = 1limn→∞an=1
∑n=1∞∣an∣\sum_{n=1}^{\infty} |a_n|∑n=1∞∣an∣ converges.
limn→∞an=0\lim_{n \to \infty} a_n = 0limn→∞an=0
∑n=1∞an2\sum_{n=1}^{\infty} a_n^2∑n=1∞an2 converges.