Answer Happy

T/F?
1. The special name given to the series n=1∑∞​n1​ is the harmonic series. 2. The sum of the geometric series n=0∑∞​arn is 1−ra​ for all r∈R. 3. If n→∞lim​an​ does not exist or if n→∞lim​an​=0, then the series n=1∑∞​an​ is divergent. 4. A series n=1∑∞​an​ is absolutely convergent if the series of absolute values n=1∑∞​∣an​∣ is convergent.