Which conditions guarantee that an alternating series ∑n=1∞(−1)nan\sum_{n=1}^{\infty} (-1)^n a_n∑n=1∞(−1)nan (where an>0a_n > 0an>0) converges?
ana_nan is decreasing and limn→∞an=0\lim_{n \to \infty} a_n = 0limn→∞an=0.
ana_nan is increasing and limn→∞an=L>0\lim_{n \to \infty} a_n = L > 0limn→∞an=L>0.
ana_nan is constant.
∑n=1∞an\sum_{n=1}^{\infty} a_n∑n=1∞an converges.