The Direct Comparison Test
Given N, if
0
£
a
n
£
b
n
for all n > N, then
if
¥
å
n = 1
b
n
converges then
¥
å
n = 1
a
n
also converges
if
¥
å
n = 1
a
n
diverges then
¥
å
n = 1
b
n
also diverges