#1: Use the divergence test. If , then the diverges.
#2: Use the fact that if converges, then so does . Then make use of the comparison test by using
I need some help with these series problems, i do not know what test to use on them. Help appreciated thanks (also i do not know how to type a summation symbol).
Summation n=0 to infinity 13arctan(n)
summation n=1 to infinity sin(43n) / 1+n^2
#1:
#2: You can't use a direct comparison because one of the conditions of the comparison test is that the terms of your sequence has to be positive for all integers after some th term.
This is why we consider the sequence where all terms are obviously positive and is why the theorem I gave you is useful.
So:
Can you finish?