Answer Happy

T/F?
1. The power series n=1∑∞​nxn​ converges for all x. 2. The power series n=0∑∞​n!xn​ converges for all x. 3. If a power series n=0∑∞​an​xn converges at x=1, then it must converge at x=−1. 4. If a power series n=0∑∞​an​xn converges at x=2, then it must converge at x=−1.