consider ∑ n=1
[infinity]

a n

. If ∑ n=1
[infinity]

∣a n

∣= 21
q2

, then (a.) the ∑ n=1
[infinity]

a n

diverges (b) the ∑ k=1
[infinity]

a n=1
[infinity]

is conditionally convergent (c) the ∑ k=1
[infinity]

a n

is conditionaliverge or may diverge - we cannot conclude d. the thanis absolutely canvergent e.) the ∑ n=1
[infinity]

a n

converges to 29
92